• Watch Out for Scammers!

    We've now added a color code for all accounts. Orange accounts are new members, Blue are full members, and Green are Supporters. If you get a message about a sale from an orange account, make sure you pay attention before sending any money!

Back from the range. My 2 rimx builds were on the back burner as the outing was to verify 0 and some dope on a few of my long range hunting rigs as we leave to go elk hunting in a week. But of course wanted to see if they would shoot... At the very end (almost dark) I grabbed them both. Took 3-4 shots at 50 to do a quick zero. Then loaded 10 rounds in each mag. Handed one rifle to a buddy who really doesn't ever shoot. May even of been his first time off a bipod and prone and the other rifle to my girlfriend who only occasionally shoots and said lets see who does better... They both seemed to feed fine and shoot fine with center x. But maybe only 13-15 rounds through both. Here's their very amateur 10 shot groups at 50. I'm just happy I didnt have major issues.
 

Attachments

  • 1016202015a.jpg
    1016202015a.jpg
    372.5 KB · Views: 66
  • 1016202015.jpg
    1016202015.jpg
    362 KB · Views: 50
I recieved my BA action back from John earlier this week. The first time I sent it back to him, he polished the chamber and put a larger than normal chamfer on the face of the barrel to improve feeding issues I was having. Upon reinstalling and heading to the range, I was having light strike issues, so I sent it back again.

Ray at zermatt though it may be a trigger issue ( TT diamond 2 stage), and John had no issues with ignition using a Bix n Andy tacsport on my BA, so I was beginning to think the trigger was the culprit. John suggested that he re-chamfer the barrel while it was their back to original spec since he was thinking the original feeding issue and maybe the light strike issue were caused by the tensioner, not the chamfer.

I got everything buttoned back up this morning and took it out to my local indoor range ( only 25 yds) just to see how it would feed and if the light strikes continued. I'm happy to report that through 170 rounds, I had no feeding issues OR light primer strikes. I ran 50 rounds of SK standard plus, 50 of rifle match, and 70 of pistol match. I'm not sure what changed, but the rifle is finally functioning properly. I'm keeping my fingers crossed it continues to do so, I'm going to try to get 1000 or so rounds through her next week on my "stay"cation.

RimX
24 inch Keystone Accuracy Bartlien M24
TT Diamond 2 stage trigger
Athlon Ares ETR 4.5-30×56
Warne Skyline precision mount
XLR industries Envy Pro chassis
Atlas Cal BT65 w/ Area419 Arca clamp
 

Attachments

  • 20201017_122943.jpg
    20201017_122943.jpg
    542 KB · Views: 94
  • 20201017_122856.jpg
    20201017_122856.jpg
    493.2 KB · Views: 94
I’ll chime in as well.

Got my BA w/ Bartlein from Keystone and been using it with a Tubb T7T. With Center X and SK, initially got almost 50% light strikes. Spoke with Ray and he sent a new fire control group. Since then, about 120 rounds and far fewer light strikes; five, if memory serves.

Emailed the same information to Ray and awaiting his thoughts.

No feeding issues at all (KRG W3 chassis).
 
What's everyone's favorite to shoot out of them so far. I just have shot center x through mine and going to try and pick up some more for later. Should I just buy more center x? Some form of sk? Eley? Etc. I dont mine spending a little money but dont like wasting if not needed. I just want accurate well feeding rounds. I do shoot more "long range" then 50 yrd groups. But these are my first 22's of this level. Always just had your average old 22lr/ 10/22 etc. Ive been big into the custom centerfire stuff and ELR world for awhile and built these as ways to gets more trigger time and have fun for "cheap". Thanks!
 
Last edited:
What's everyone's favorite to shoot out of them so far. I just have shot center x through mine and going to try and pick up some more for later. Should I just buy more center x? Some form of sk? Eley? Etc. I dont mine spending a little money but dont like wasting if not needed. I just want accurate well feeding rounds. I do shoot more "long range" then 50 yrd groups. But these are my first 22's of this level. Always just had your average old 22lr/ 10/22 etc. Ive been big into the custom centerfire stuff and ELR world for awhile and built these as ways to gets more trigger time and have fun for "cheap". Thanks!
Mine shoots Center X well(some lots really well) and most all of the SK offerings. I just bought some RWS R50 and RWS rifle match. I’ve shot a couple of groups with the RWS and it’s looking like it’s going to shoot them decent as well. I’ve tried several Eley brands(match,club,target,contact and team) they didn’t perform very well out of mine. 18” Green Mountain with Padom’s reamer.
 
Mine shoots Center X well(some lots really well) and most all of the SK offerings. I just bought some RWS R50 and RWS rifle match. I’ve shot a couple of groups with the RWS and it’s looking like it’s going to shoot them decent as well. I’ve tried several Eley brands(match,club,target,contact and team) they didn’t perform very well out of mine. 18” Green Mountain with Padom’s reamer.

Good to know. I may stick with center x. But was looking at the some of the SK lines as well as maybe another descent choice. Just want a few options with todays low supply and high prices
 
I continue to shoot SK+, SK RM and CX and have no reason to search elsewhere with the accuracy Im getting across 8 barrels tested now.

Here is a forum members barrel he sent me to look at/test that was having some accuracy and feeding issues. Ill leave it up to that member to decide if he wants to claim it but it doesnt really matter. Its a Keystone Accuracy Green Mountain with my 22LR Match Eachus chamber.

Barrel shot great, zero feeding issues and accuracy on some lots was great. When I received the barrel, I scoped it and saw some carbon or some type of build up in the front half of the chamber closest to the lands. I cleaned the barrel with BoreTech RimFire blend but it didnt remove that chamber build up. I spun some either 00 or 000 steel wool (whatever I had on the bench) in the chamber on a dremel and it removed that build up quickly and left a nice polish on the chamber. I then patched it out and screwed it on my RimX. Torqued to 55 ft lbs.

I loaded a 10rd mag 10x, running the bolt for those 100rd and it fed perfectly. Zero feeding or ejection issues and no hard bolt close. I then took it to the range and shot 8rd of SK+ on the clean cold bore at 50yd. I then shot a 5 shot group with that same lot of SK+. I then shot 4 lots of CX, then 3 lots of SK RM. All randomly grabbed partial boxes laying in the bottom of my bag from previous testing.

As you can see, it loved some lots, and didnt like some others but all in all accuracy was great for not doing proper lot testing.... No barrel fouling, no cleaning between ammo, no multiple groups of each lot.

Also, for those of you that maybe measure your groups a different way or subtract a different #, the group sizes noted on the targets below are measured outside to outside black smudge ring minus 0.223". So if you subtract a different number, add 0.223" to those group sizes and you will have outside to outside measurements...










 
Where are all the guys from the Bartlein carbon fiber group buy??!!! I thought we would have seen a few results by now. AdamB is the only one I've seen any results from. Where the 6x5 and/or 100yd testing with different lots??

I dont own one so I was curious to see how they shot.
 
Last edited:
Where all the guys from the Bartlein carbon fiber group buy??!!! I thought we would have seen a few results by now. AdamB is the only one I've seen any results from. Where the 6x5 and/or 100yd testing with different lots??

I dont own one so I was curious to see how they shot.

Me too!
 
So just an update on my RimX. From Keystone. Couldn't chamber rounds correctly, shaving brass. I Brought it to my gunsmith today to have him look at it. Won't mention names, but Zermatt boys know him. Upon inspection his comment was it is the worst looking chamber job he's seen in 40+ years! Rechambered it with one of his match Reamers, re chamfered the breach, was really rough, stoned the tensioner, cleaned up the Extractor shoe. Ran two mags as fast as I could behind his shop, Perfect! No failure to feed, extract, or fire. This kind of work is giving the RimX a unwarranted, bad reputation.
Ray has been very helpful and is sending out a extra tensioner and extraction shoe. I'll start figuring Ammo preference Wednesday. As much as I didn't like Orkans presentation on the issues, he's spot on. 22s are not like centerfire rifles and require a smith who is intimately familiar with them. It doesn't mean you need to get bent over to get one done correctly. The 22 game is kinda new and requires a different skill set and knowledge to get it right. Not every smith has that skill set. I'm confident the RimX will be a fantastic 22 when done correctly.
 
Follow up on the RimX. So, my knee jerk post on my experience has raised some hackles and rightfully so. Both with Zermatt and Keystone. First, I would encourage anyone who is having problems with their Keystone barreled RimX to contact John to make it right. I had a long conversation with him on the issues this morning. Second, in all honesty I should have contacted him first to give them a chance to rectify it. Again Knee jerk, I was pissed. The chamfer should be a radius, growing pains. Also, a new Reamer to address this is on the way. I was fortunate to have a fix close and quick, not everyone does.
 
  • Like
Reactions: Criver600
...The chamfer should be a radius, growing pains. ...

The Rimx tenon print calls for ".005-.010 Chamfer or Radius on Chamber Mouth High Polish Recommended".

Did Zermatt or Keystone says it should be radius? I've been making mine with a highly polished chamfer and it feeds pretty darned well.
 
K
The Rimx tenon print calls for ".005-.010 Chamfer or Radius on Chamber Mouth High Polish Recommended".

Did Zermatt or Keystone says it should be radius? I've been making mine with a highly polished chamfer and it feeds pretty darned well.
Keystone, thats what my Smith did yesterday. More like polishing the Chamfer. Feeds fantastic now.
 
I just have my problem bolt back from zermatt,still getting some HICCUPS email ray about it follow his instruction adjust mags height then i found the spot that works on the bolt but still weak options. This is what happen now after emails back and forth etc etc. TRY TO CHAMBER ROUNDS FROM MAGAZINE THEN REMOVE MAGAZINE CHECK IF THE SHELL CONTACT THE EJECTOR. IT WORKS VERY VERY WEAK THE SHELL JUST EJECT FROM EJECTOR THEN DROP BELOW THE MAGAZINE CUT WITHOUT THE MAGAZINE.EXTRACTION/CHAMBER HAS A FEW PROBLEM NOW 8 OUT OF 10 WORKS THEN AMMO WENT BEHIND THE EXTRACTOR/TENSIONER BUT THE BIG PROBLEM IS THAT IT WILL NOT SPENT THE SHELL OUT AND AWAY THE ACTIONS. So i try my other bolt the same set up WOW WORKS FLAWLESS THE SHELL EJECT ON THE SIDE OF THE ACTION SPENT SHELL OUT ON THE SIDE AWAY AND YOU CAN FELL THE SHELL EJECT FROM THE SIDE OF THE ACTION.
I email ray Again that this is going of this problematic bolt,any body can chime in if zermatt and me miss something wrong(VERY VERY WEAK EJECTIONS OF SHELL AND SOMETIMES THE AMMO WENT BEHIND THE EXTRACTOR/TENSIONER 8 OUT OF 10 WORKS BUT THE REST IS NOT)this bolt was send to zermatt and i have it 2 days to date only from repairs.Thanks in advance

Thank you Ray of Zermatt! I just received the complete bolt face assembly that you send me even though I don't ask for it.My problematic bolt is not a problematic anymore it turns out to be smooth,flawless and works like a charm now.Thank you ray for your help!
 

Attachments

  • DSC02275.JPG
    DSC02275.JPG
    642.2 KB · Views: 78
  • DSC02276.JPG
    DSC02276.JPG
    169.5 KB · Views: 83
Gun is together got the stock opened up no issues, trigger installed i did try to remove thr firing pin and boy just didnt want to pop off so i gave up for now

Going to switch out the bolt knob and unfortunately was sent the wrong brake so will need to get that exchanged i threw a spare a2 on now to protect the threads

I habe a spare viper pst 4-24 i will throw on it for now but will eventually end up with a strike eagle to match my 6.5
 
So, after having my chamber Reamed with MY smiths match reamer and polished. It feeds fantastic! Just got back from a little range session to get it zeroed, crap ammo, SK long range.
I'm thinking it has potential. Only 250ish rounds on it but feeling good.
200 yards. Bipod, bag, off the ground, 45*, 4mph switching wind from 7-9
 

Attachments

  • 20201021_085723.jpg
    20201021_085723.jpg
    688.7 KB · Views: 58
Had some new lots of SK+, SK RM, CX and R50 I got out and tested today at 50yds. Shot 50rd each prone, rear bag out of my 20" Bartlein with Rugged Oculus attached. Didnt really have any terrible lots in todays testing. I was happy with all of them. RimX is still running great going over 6500+ rounds on my setup today.

All groups are outside to outside black smudge ring minus 0.223. Add .223 if you want the outside to outside numbers.









 
Swung by my folks farm this evening to show my dad his rimx and to do a little shooting. I have put about 150 rounds through both his and mine each. The chamber bolt etc has been fairly rough on both but wasnt having any other bigger issues. Until today... Pulled his out and loaded up 10 rounds. All lite strikes... Zero fired. We ended up getting it to fire but about every 3-4 for the next 20 were lite strikes. We gave up after that. Will see if somehow something got outa adjustment?
 
  • Like
Reactions: Baracuda22
Talked to Zermatt last week and they want me to send my bolt head in. Been working late every day so it may be a while before I get a chance. As of now the best it will do is about 80% making it to the chamber in the boltface. I can see a few things that i think stoning would fix but will let them do their thing. They have been very helpful and I have no regrets on my purchase. John said to send the barrel in and he would work it over. Its a busy time of year for me so may be a little before I get it up and running.
 
Last edited:
  • Like
Reactions: Baracuda22
Swung by my folks farm this evening to show my dad his rimx and to do a little shooting. I have put about 150 rounds through both his and mine each. The chamber bolt etc has been fairly rough on both but wasnt having any other bigger issues. Until today... Pulled his out and loaded up 10 rounds. All lite strikes... Zero fired. We ended up getting it to fire but about every 3-4 for the next 20 were lite strikes. We gave up after that. Will see if somehow something got outa adjustment?

Checked your trigger sear, bolt cocking piece engagement?
 
Swung by my folks farm this evening to show my dad his rimx and to do a little shooting. I have put about 150 rounds through both his and mine each. The chamber bolt etc has been fairly rough on both but wasnt having any other bigger issues. Until today... Pulled his out and loaded up 10 rounds. All lite strikes... Zero fired. We ended up getting it to fire but about every 3-4 for the next 20 were lite strikes. We gave up after that. Will see if somehow something got outa adjustment?
A couple of things to check here.

First, what trigger are you using? However not likely to be the cause, there's definitely potential here.

Second, have you cleaned the firing pin assembly? Some people will clean all of the grease out of actions that we ship them with and this is a bad practice. We lubricate areas that need lubrication when they go out the door and advise you keep them that way. If you haven't already, try adding some lubrication on the firing pin shaft and inside of the shroud. We've had some (very few) of these RimX firing pin assemblies gall between the shaft and shroud. We made a change on the treatment of the shaft and are now nitriding them to create a thicker, harder case on the shaft. Most of the original treated shafts have been performing perfectly fine and I wouldn't be concerned about the potential for light strikes if you haven't encountered them at this point. The way to tell if you have an original shaft or a nitrided shaft is the color. Originals will be blue and nitrided will be black.

Third, check the head space on the barrel. Again, not likely to be the cause, but still potential. Remove the extractor first (1/16" Allen wrench) and use the supplied no-go gauge to verify there isn't excessive head space.

If all of this leads you to the same result, please reach out to us and allow us to work through this with you.

Thank you - Ray
 
I build several Rimx rifles in my shop. I personally think they are a great action. Different than anything else for sure. Feeding issues from what I’ve seen have been no worse than any other rimfire. You do need to be sure your magazine is adjusted perfectly though. Very critical.
The Rimx is different in the chamber/ headspace as well. You must set your chamber bullet jam correctly. When done so you will be very pleased. You must also know how to properly polish a chamber. A rimfire can not shoot itself smooth. Well maybe it can but your talking thousands of rounds. When polished properly your good to go from shot number 1. I think these two areas are where some guys fail. There isn’t a lot of info out there on these subjects. I am lucky to have some of the best in the buisness as friends and mentors. You can’t chamber a rimfire like you would a centerfire. You just can not!!! I love the Rimx but I also like the Vudoo stuff. Vudoo will always be the leader in this sport rightfully so. The new single shot will be a great addition. I can’t wait to get mine. Will it out perform my 2500x? We shall see!
Lee Gardner Precision
Mattoon illinois
 
Folks, I just got my new threaded barrel for RIM-X. Chamber: My Own Match Chamber PRS(Personal Research Spec. Reamer)
Barrel: Lilja 3g/16t 22" useable Length
Chamber:Bullet engages the rifling with about more than 1/8th inch. of brass left to go in.Ammo seen: Center-x
My Rim-X new bolt face:Licking it very much on this combo.
 

Attachments

  • DSC02274.JPG
    DSC02274.JPG
    711 KB · Views: 117
  • DSC02272.JPG
    DSC02272.JPG
    650.6 KB · Views: 120
  • Like
Reactions: JKW70
I build several Rimx rifles in my shop. I personally think they are a great action. Different than anything else for sure. Feeding issues from what I’ve seen have been no worse than any other rimfire. You do need to be sure your magazine is adjusted perfectly though. Very critical.
The Rimx is different in the chamber/ headspace as well. You must set your chamber bullet jam correctly. When done so you will be very pleased. You must also know how to properly polish a chamber. A rimfire can not shoot itself smooth. Well maybe it can but your talking thousands of rounds. When polished properly your good to go from shot number 1. I think these two areas are where some guys fail. There isn’t a lot of info out there on these subjects. I am lucky to have some of the best in the buisness as friends and mentors. You can’t chamber a rimfire like you would a centerfire. You just can not!!! I love the Rimx but I also like the Vudoo stuff. Vudoo will always be the leader in this sport rightfully so. The new single shot will be a great addition. I can’t wait to get mine. Will it out perform my 2500x? We shall see!
Lee Gardner Precision
Mattoon illinois
I build several Rimx rifles in my shop. I personally think they are a great action. Different than anything else for sure. Feeding issues from what I’ve seen have been no worse than any other rimfire. You do need to be sure your magazine is adjusted perfectly though. Very critical.
The Rimx is different in the chamber/ headspace as well. You must set your chamber bullet jam correctly. When done so you will be very pleased. You must also know how to properly polish a chamber. A rimfire can not shoot itself smooth. Well maybe it can but your talking thousands of rounds. When polished properly your good to go from shot number 1. I think these two areas are where some guys fail. There isn’t a lot of info out there on these subjects. I am lucky to have some of the best in the buisness as friends and mentors. You can’t chamber a rimfire like you would a centerfire. You just can not!!! I love the Rimx but I also like the Vudoo stuff. Vudoo will always be the leader in this sport rightfully so. The new single shot will be a great addition. I can’t wait to get mine. Will it out perform my 2500x? We shall see!
Lee Gardner Precision
Mattoon illinois
Is it better than Vudoo it looks like a lot of owners are having trouble. Shaving brass and trigger problems, Have you ever had these problem with a Vudoo. I have shot a few guns you have built. You have allways been honest.
 
I think ALL the problems people are experiencing with the RimX is the chamber job. As Lee has said, chambering a 22 is a different deal.
Mine is running real well now. I think if you get a knowledgeable 22 smith to chamber it, you'll be good to go.
 
Could someone give a "dummy's guide" to the chamber and feeding issues if possible? I've no skin in the game or anything, just like reading about rifles and shooting and am following this thread. Maybe there are others out there similar to me too. From what I've seen, the Rim X is similar to a Vudoo in that they use a controlled round feed. The cartridge snaps up under the fixed extractor from the magazine (can be seen demonstrated in a YouTube video by Primal Rights) and is held in line with the bore/chamber while it's still clear of the chamber. As the bolt is pushed forward, the round should be already aligned and feed straight in. That's my understanding so if someone could explain what then goes wrong and what the chamber has to do with it, it would be much appreciated. Thanks in advance.
 
I don't think there will be any issue if its chambered and polished correctly. Also I believe the RimX calls for a slight chamfer at the breach that needs to be polished too. Again, mine runs really smooth now.
 
Got my rimx finished and ready for the range

Manner t4a with mini chassis
Proof 20in
Trigger tech primary
Viper 6-24

Currently has a dd a2 on thread protection duty but will prolly order a hellfire 2 port so it matched the 6.5cm big brother

Built the 6.5 earlier this year and it was the first rifle ive build from scratch and the first bolt gun ive had that wasnt a base 700.....well thanks to the info and help sh has provided and the customer service i got from these companies i justified building a 2nd one sure the wife is pissed ive got $3600 in a 22....oh well
 

Attachments

  • 20201028_232134.jpg
    20201028_232134.jpg
    303.7 KB · Views: 156
Ahogue, That stock appears to be a T2A, not a T4A. Maybe if your wife would start shooting the RimX with you, she'd learn to appreciate it rather than be PO'd about it...lol
 
Thats correct and it is a t2a and shes just likes to give me crap but she is like me and is just particular about how guns feel she seems to like the feel of chassis rifles more than standard stocks she will have her own bolt gun at some point but she has a dd mk12 she really enjoys
 
  • Like
Reactions: Hunting2019
That's because virtually every rimfire ever made is "controlled round feed" to some degree. Especially every design with dual extractors or a tensioner design.

I'm just trying to wrap my head around the problem as a casual "thread reader". So, in my head this is the way things happen: The bolt pushes the cartridge forward and out of the magazine. During this process the cartridge rim gets pushed up and is held by the fixed extractor. The cartridge is totally free from the barrel at this stage but is concentric to the bore and is just awaiting to be fed straight in. Then as the bolt proceeds forward the bullet tip enters the chamber - it still hasn't contacted the barrel yet due to the bullet having a tapered tip. It's not until the driving band area meets the chamber that the bullet actually meets the metal of the barrel/chamber and at this stage the very tip of the bullet is already inside the chamber lets say 4 to 5 mm.

So where from here does the insertion of the cartridge into the barrel start to go wrong? Or has something already started to go wrong at this stage? It would appear that the tapered nose of the bullet that's already in the chamber has provided a lead for the cartridge to continue on it's way and also, from the Primal Rights video on YouTube the cartridge seems very well aligned with the bore regardless.

I've read from Zermatt the entrance of the chamber needs a very small polished radius to it. Is this to facilitate the driving bands not snagging if the entrance to the chamber is very tight?

Again, I'm not trying to argue, cause offense, or anything of the sort. I just like to understand how things work in general and have an interest in the operation of things in my hobbies. So far I've read that some people have had problems feeding rounds with this rifle. The cause that's suggested is the chambering or the person who did the chambering not being familiar with the intricacies of rimfire guns. But what is it exactly with the chamber, what's the crux of the problem? Thanks.
 
The cause that's suggested is the chambering or the person who did the chambering not being familiar with the intricacies of rimfire guns. But what is it exactly with the chamber, what's the crux of the problem? Thanks.
From the issues that we've seen pictures of or had hands on the product, the chamber has been left unpolished. Some have had what we feel to be relatively aggressive tool marks in them that, when paired with the tight chamber mouth, are creating snags and inconsistencies in the feed cycle.

A clean chamber is always ideal. Tool marks in chambers are never ideal. Clean machining isn't the easiest thing in the world to produce so some are left to finish the job by polishing. It doesn't take much polishing to remove .001" of material. If you have some time, take a look at the variety of chambers and the dimension of each of their mouth's. That .001" can make the difference between this chamber and that one.

All in all, clean machining is key.

Thanks - Ray
 
IMHO, having a wife who appreciates fine rifles and likes to shoot is priceless! It's the best of both worlds, to put it mildly.
Yeahhh until you have to build her a centerfire and rimfire cause she beats the boys. Sounds like another TL3 and RimX is gonna be under the xmas tree.

She needs a sponsor haha
 
  • Like
Reactions: Hunting2019
I have a RimX BA with a Bartlein barrel on order with John at Keystone. My order for this choice was predicated by the 10 barrel test done with both RimX and Vudoo actions that was posted earlier on the Hide. The chamber used with the RimX actions was the Padom chamber as reamed by Keystone. I was greatful for the time, energy, and money, that was put into this test which contributed to my making an up to date decision.
There have been some questions regarding what is being discussed here (chamber wise) and I think that it is well outlined in the “Knowledge Base” section over ay Keystone’s web page. Its a good read. Here’s the link.
 
  • Like
Reactions: kampr and Schütze
I have a RimX BA with a Bartlein barrel on order with John at Keystone. My order for this choice was predicated by the 10 barrel test done with both RimX and Vudoo actions that was posted earlier on the Hide. The chamber used with the RimX actions was the Padom chamber as reamed by Keystone. I was greatful for the time, energy, and money, that was put into this test which contributed to my making an up to date decision.
There have been some questions regarding what is being discussed here (chamber wise) and I think that it is well outlined in the “Knowledge Base” section over ay Keystone’s web page. Its a good read. Here’s the link.
I'm glad not everybody listens to the guys "bashing" the RimX platform or John at Keystone. I've one of his barrels and no chamber or other issues with it at all. The rifle performs very well for my limited knowledge. I'd like to mention that I've only used center-X and sk+, it was clearly stated by padom that this chamber is cut / head spaced for lapua / sk ammo. I'm wondering sometimes if owners with issues trying different ammo like cci perhaps. I use a tt diamond and have not experienced a lite strike yet in a little over 1000 rounds.
 
I'm glad not everybody listens to the guys "bashing" the RimX platform or John at Keystone. I've one of his barrels and no chamber or other issues with it at all. The rifle performs very well for my limited knowledge. I'd like to mention that I've only used center-X and sk+, it was clearly stated by padom that this chamber is cut / head spaced for lapua / sk ammo. I'm wondering sometimes if owners with issues trying different ammo like cci perhaps. I use a tt diamond and have not experienced a lite strike yet in a little over 1000 rounds.
I am using the keystone bartlein barrel as well and have short cci, eley, and center x through my rifle. I have had one time where a round failed to be caught under the tensioner (sadly in a match) and otherwise no issues. I have put about 1300 rounds through my rifle and haven't had to clean it. I am also using the TT diamond.