Any one know the oal capacity of the 300 PRC magazine? I'm looking at a custom barrel chambering and want to know if it will fit.
- Thread starter IanHusaberg
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The SAAMI spec for .300 PRC OAL is 3.575-3.700" the B magazine for 300wm has internals of 3.8. Obv you will want it a little short to ensure feeding. 
Thank you! Mine should be here tomorrow
Looks like a great fit. Grabbed their CAL65, too, and an MLOK mount in case the ARCALOC is just too much.Agreed! They did a great job with it!
Thanks,
I have a friend that custom chambered 3 barrels with a shorter lead to allow Berger's to seat deeper in the case neck. I'll see what his COAL turns out to be. Certainly shorter than it is now.
The fix it sticks are great but I wasn't able to find the 140 in-lb without buying the kit from Barrett.
They sell it individually, LMT people need it too.
I like the kit as it is well thought out, but man, the price on that thing.
this is straight facts.
The same kit from fix it stix is far and away cheaper.... but they are always out of stock for the 140lbs torque limiter which pretty much makes the buying of the MRAD Kit the only reliable way of getting one (atm)
Not that I'm aware of. I wish i could get an unfinished .308 or .300 mag to file feed lips myself to run a 6.5saum.
Hello,
does anyone know what a safe headspace measurement could be for the .338LM version? Can't find any SAAMI specs for this cartridge.
Bought some 1F LAPUA 338LM brass online and getting ready to handload. It's measuring at 2.327-2.328" (Hornady headspace gauge) and will not allow the bolt to close even when pushing forward on the bolt. I have been incrementally bumping the shoulder and can now chamber brass measuring 2.322" headspace. This still requires a light forward push of the bolt before it will turn down. I have tried bumping the shoulder as much as I can down to 2.315" and still the bolt won't close freely without forward push - like it does when no brass is being inserted into the chamber.
I hope I've explained this coherently enough that someone can offer me guidance.
Thanks.
does anyone know what a safe headspace measurement could be for the .338LM version? Can't find any SAAMI specs for this cartridge.
Bought some 1F LAPUA 338LM brass online and getting ready to handload. It's measuring at 2.327-2.328" (Hornady headspace gauge) and will not allow the bolt to close even when pushing forward on the bolt. I have been incrementally bumping the shoulder and can now chamber brass measuring 2.322" headspace. This still requires a light forward push of the bolt before it will turn down. I have tried bumping the shoulder as much as I can down to 2.315" and still the bolt won't close freely without forward push - like it does when no brass is being inserted into the chamber.
I hope I've explained this coherently enough that someone can offer me guidance.
Thanks.
It is a comparator. The measurements someone else gets with their calipers/body/insert can be different than what you measured even if you sent them the same piece of brass.
Ideally you'd make the comparison against brass that was fired in your rifle. Worst case use an unfired piece of brass or the modified case from the Hornady OAL tool to compare against what is the minimum and what has proper "feel" on bolt close for your re-sized sourced once-fired brass.
Calipers are cheap, I dedicate one for the comparator so the body stays in the same spot and my historical noted measurements have consistency for ME, they wouldn't be of use to you.
That’s because of the ejector spring being so strong. You are applying the forward force to compress the spring as it seats into the bolt face.
I have to do the same with my new MRAD and also with my AXSR.
Take the ejector spring out and you’ll see that forward push disappear.
This is the way.
Remove the ejector and spring before attempting to find how much you need to bump the shoulder.
If you want to find the place where your bullet will be no longer touching the rifling of the barrel, you do pretty much the same thing.
There are tubervideos about how to do it.
Just joined the forum today. Reading back a while and I hope this helps some of you guys. I’ve had a lot of interaction with the Barrett crew, learned a lot, and I have 3 MRADs and a few other of their products. So hopefully what I’ve learned will help. I have a CJ MRAD and two EJs. I run all the barrels in any of them due to the following knowledge.
AJ000250 (I believe) or less will require screw slots to be cut into the barrel (Barrett does this free of charge and sends labels if you buy used or what not) These MRADs will require the screws to be completely removed. This is essentially a super early MRAD. They are “slick” side uppers and do not have lightening cuts at all.
After the AJ000250 essentially all the way up to the high AJs. There is no exact number range FYI. Anything past AJ002000 could possibly be a small breech. Anything before that I would obviously confirm. I do not have photos showing this but primarily they were .338 LM rifles and the bolt bodies, bolts, and front and rear guides were much larger. This is where your LARGE TO SMALL BREECH CONVERSION comes into play. You will need this to use/purchase any MRAD barrel kit from now On. As everything is small breech now for uniformity.
CJ prefix rifles are the lightening cut rifles (still not MLOK). Barrett doesn’t do “Generations” on these but think “GEN 2” if it helps. IF you have a small breech AJ or a CJ across the board you can use ANY Barrett MRAD kit. I have attached two photos to show why. The bolt pins and bolts are the cause of this. So to reiterate…. CJ and AJ (only those who have done the conversion) can use ANY new Barrett kit or even used kit they find. Also, if you just want a new upgraded EJ/MK22 firing pin that has the fancy flip lever? 18818 is the part number and Barrett sells it stand alone. It is handy and you can keep yours as a spare. You’ll have to call and order it and it will be built to order (2-3 weeks usually).
Now here we go. The EJ / MK22 rifles. You guys can get by super easy too. IF You came across any used barrel kits or discounted Barrett kits. Guess what? You actually don’t need the large to small breech conversion kit to run those barrels. You need 3 pieces. Yes 3 parts only. Bolt tube, bolt knob, and bolt pin. It is about 187 dollars retail for those 3 parts. Plus shipping or tax of course. You’ll have to call and ask for a “CJ bolt tube, bolt knob, and bolt pin” and they can help you out. They are in stock and can ship within the week. Their shipping department is still meh but it’ll get out
Within 2-3 days.
As for the MRADELR questions I just saw. There are zero plans for the .50 BMG. The .416 and the 375 Enabler seem to be the only thing on the table for now. I asked about Cheytac and they hinted maybe in the future but not for a while. Edit: while the bolt face of the .416 May handle .50 BMG I’m unsure even if you wanted to single feed if it would work. Maybe M33? But long loaded AMAX or similar probably wouldn’t fit. Or it would be extremely impractical.
If you guys are confused, emailing into Barrett always helps me as I get better responses via email than phone usually for just product / inquiry knowledge.
AJ000250 (I believe) or less will require screw slots to be cut into the barrel (Barrett does this free of charge and sends labels if you buy used or what not) These MRADs will require the screws to be completely removed. This is essentially a super early MRAD. They are “slick” side uppers and do not have lightening cuts at all.
After the AJ000250 essentially all the way up to the high AJs. There is no exact number range FYI. Anything past AJ002000 could possibly be a small breech. Anything before that I would obviously confirm. I do not have photos showing this but primarily they were .338 LM rifles and the bolt bodies, bolts, and front and rear guides were much larger. This is where your LARGE TO SMALL BREECH CONVERSION comes into play. You will need this to use/purchase any MRAD barrel kit from now On. As everything is small breech now for uniformity.
CJ prefix rifles are the lightening cut rifles (still not MLOK). Barrett doesn’t do “Generations” on these but think “GEN 2” if it helps. IF you have a small breech AJ or a CJ across the board you can use ANY Barrett MRAD kit. I have attached two photos to show why. The bolt pins and bolts are the cause of this. So to reiterate…. CJ and AJ (only those who have done the conversion) can use ANY new Barrett kit or even used kit they find. Also, if you just want a new upgraded EJ/MK22 firing pin that has the fancy flip lever? 18818 is the part number and Barrett sells it stand alone. It is handy and you can keep yours as a spare. You’ll have to call and order it and it will be built to order (2-3 weeks usually).
Now here we go. The EJ / MK22 rifles. You guys can get by super easy too. IF You came across any used barrel kits or discounted Barrett kits. Guess what? You actually don’t need the large to small breech conversion kit to run those barrels. You need 3 pieces. Yes 3 parts only. Bolt tube, bolt knob, and bolt pin. It is about 187 dollars retail for those 3 parts. Plus shipping or tax of course. You’ll have to call and ask for a “CJ bolt tube, bolt knob, and bolt pin” and they can help you out. They are in stock and can ship within the week. Their shipping department is still meh but it’ll get out
Within 2-3 days.
As for the MRADELR questions I just saw. There are zero plans for the .50 BMG. The .416 and the 375 Enabler seem to be the only thing on the table for now. I asked about Cheytac and they hinted maybe in the future but not for a while. Edit: while the bolt face of the .416 May handle .50 BMG I’m unsure even if you wanted to single feed if it would work. Maybe M33? But long loaded AMAX or similar probably wouldn’t fit. Or it would be extremely impractical.
If you guys are confused, emailing into Barrett always helps me as I get better responses via email than phone usually for just product / inquiry knowledge.
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Finally got a .308 barrel and I'm looking to take the factory brake off of it -- I'm assuming they've threadlocked it to hell and back, so the best solution is probably to clamp it in a vise, heat the brake, and go to town, right? Seems to not be the newer style brake without the additional nut behind it.
Yep. Red loctite up and down those threads. Small Propane torch worked best for me and thrown into a barrel vise.
I was working on a prototype, but the problem is that the current mags are at the near maximum in terms of spring travel. When you remove the factory floor plate, there is only room for maybe 1 extra round for an extension before the spring would be fully extended - this would lead to unreliable feeding on the last round or two with any extension and lack of modification to factory springs.
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Ordered (barrel makers kit) on 29DEC2023 and received on 25JAN2024. Basically a month.
I ordered a .308 "C" as well in November and took about a month as well.
I changed my plans and put it up on PX last night if anyone is looking to save some cash.
Did a little searching without much luck. Does anyone happen to know the official Mk22 HOB? My quick measurements were 1-7/16" to the top of the rail, then the factory Nightforce Ultramount should be another 1.54" from there. My figure is 2.97"
ETA: Based on where I measured, I'm just going to assume Barrett chose a rail height that shakes out to 3.0" with a standard CNVD compatible 1.54" mount.
ETA: Based on where I measured, I'm just going to assume Barrett chose a rail height that shakes out to 3.0" with a standard CNVD compatible 1.54" mount.
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My Barrett MRAD Bugholes (Souther Precision Rifles) barrel should be done in a month or two.
I can't lie, I literally think about it every day I'm so excited to get it.
I went with a Bartlein 400ModBB 300 Norma Mag 32 inch barrel Heavy Varmit with a 1" muzzle diamter FDE cerakote with the standard MRAD flutes.
Plan to shoot 245 grain LRHT bullets over N565 in Lapua brass.
Plus I'm praying my FDE Thunderbeast Ultra 338 clears ATF jail soon which should make for a better shooting experience.
Anyone done something similar? Let me know your experience with bugholes barrels or any custom barrels. Interested to hear from the 300 Norma guys on here too about loads and successes with the MRAD.
I can't lie, I literally think about it every day I'm so excited to get it.
I went with a Bartlein 400ModBB 300 Norma Mag 32 inch barrel Heavy Varmit with a 1" muzzle diamter FDE cerakote with the standard MRAD flutes.
Plan to shoot 245 grain LRHT bullets over N565 in Lapua brass.
Plus I'm praying my FDE Thunderbeast Ultra 338 clears ATF jail soon which should make for a better shooting experience.
Anyone done something similar? Let me know your experience with bugholes barrels or any custom barrels. Interested to hear from the 300 Norma guys on here too about loads and successes with the MRAD.
I have a 7 PRC barrel from Marc at Spartan Precision. It is a laser beam. Uses B mags/barrel maker kit. Haven’t tried any other custom barrels besides Proof and Spartan.
I have done a bartlein modbb 300 norma at 28inches with a heavy modified palma. Was running 82grn of re26 with a 220 berger at 2970fps or 3040. Cant remember. I'm working up some loads for 245's. The barrel is a left hand gain twist starts at 1/9, exits at 1/8. Shoots great so far only 160 rounds into it. This was chambered by lri. Swatdude1 has used bugholes and has been happy with his stuff. I've had mrad barrels done by a number of smiths and they're all shooters. GAP, Spartan, LRI, PVA.
What made you go with the gain twist? Got any pictures of groups?
Nice man. What sort of velocities you getting?
I’m averaging around 2860-2880. I also don’t reload unfortunately so that’s with factory hornady 180 grain. A ten shot grouped .58 inch.
-Bartlein barrel blank, 7MM bore, 8 twist, #9 heavy varmint contour (5" long breech end at 1.250" for MRAD extension)
-Cut muzzle threads 5/8X24 at 22" finished length
Anybody know the specs for the MRAD ejector roll pin? $5.00 for a simple roll pin seems rather ridiculous so I'm looking to get some at M Carr or Grainger.
I checked the exploded view and it says it’s a .093 X 500 roll pin.
Not the AML338, but I do have lots of time behind the AM30. I’m sure there are more modern, higher volume suppressors that beat it for sound in the 8” length class, but it works great. The muzzle brake suppressor mount is high quality and locks up tight with the taper interface. POI repeatability with removal and reattaching during for cleaning is very good, I have never had a POI shift from removal. The one I shoot is about 8 years old and ~8K rounds fired, and it is still going strong. It’s a good system.
Of note, and maybe this is obvious: if you get the AML338 suppressor for 338 barrels but also have 30 cal barrels, the muzzle devices are different spec to prevent attaching the AM30 to a 338 barrel. Just gotta make sure any 30 cal barrels are also equipped with the 338 muzzle device as well for that scenario.
Dang. Responded to the wrong post and figured out I couldn't delete. I checked the exploded view and it says it’s a .093 X 500 roll pin.
Thanks for the information. Looks like it is an odd ball to find.
Now, just to figure out how to spend $100 to qualify free shipping...
Its an $1,800 accessory that you could be replaced for half the price, for a $15,000 rifle that you can actually buy for half the price. Granting that they're both cool as fuck, probably collectible, and you're already down for fiscal irresponsibility, it'd be foolish to get one and not the other.
With that in mind, I'm very happy with mine but I'm a simple man these days: the difference between 127.3 and 129.7 decibels at some arbitrary distance and angle from the shooter doesn't have any value to me anymore. It sounds great to me, and good enough that range neighbors will, unsolicited, comment. I imagine it also helps tame the 300WM recoil but that could simply be the combination of a 15.2 pound rifle and 1.6 pound suppressor, too. Regardless, the 300WM in the suppressed Mk22 is more pleasant to shoot than 308 out of my suppressed M24A2.
It's my only rifle I haven't shot unsuppressed so I can't comment on POI shift. I do remove the suppressor every outing and the zero persists. The gate/lock on the AML338 (pics a few pages back) seems to be more than enough to prevent the suppressor from loosening accidentally or intentionally and always ends up at the 7 o'clock for me when locked. I think my only meaningful commentary is that the AML338 really benefits from a wrap though the same is probably true of Thunderbeast, as well.
When I reached out to Barrett recently, they indicated that every barrel/muzzle would be compatible with the AML338. I wonder if it's like Surefire: the AM30 works on the 30's but not the 338's while the AM338/AML338 work on both the 30's and 338's. It could also just be timing as every barrel is being updated to the latest generation.
I have a 33XC Bartlein modBB barrel from Bugholes that shoots one ragged hole. Chase Stroud did the load development for me and was very impressed by SPR's work. I got two consecutive hits at 2 miles with this barrel with Chase spotting. He said no "student" had ever done that and I credit SPR for impressive smithing. I also have a non-modBB Bartlein barrel in 300PRC which has the Barrett flutes (SPR as well). I shot a 1/4 MOA group at 200 yards with Hornaday factory ammo but was never able to duplicate. But that barrel is definitely half MOA for sure. I wish I'd done flutes on the 33XC just to maintain the factory look. Now I'm waiting on a .416 modBB blank SPR ordered for me so Greg can spin me up a 41XC barrel and will definitely do Barrett flutes and Cerakote on that one.
Regarding suppressors, I ran the Barrett AM338 on the 33XC and was good without hearing protection. Had to delete the photos of me doing that because I wear hearing aids to catch speech consonants and my wife would kill me if she knew I didn't have plugs in.
@mike10 sorry just seeing this. Went with gain twist to test it, based on Snipers Hide lore. Its accurate and load development has been super easy. Usually shooting steel at 500 and further. But I'll post some pics. Funny thing was I had two identical barrels spun up and tested both with my mrad. My brother used the other barrel at the NF match. We tried shooting same ammo, scope, rifle. I'm happy with all my factory and custom mrad barrels. If its a palma contour it's slightly modified with 1.25in diameter for the first 5 inchs to accomadate the mrad extension.
6.5cm PVA 1.25 straight 1/8
6.5 SAUM GAP Light Palma 1/8.5-1/7.5
.308 Factory
300 Norma LRI Med Palma 1/9-1/8
300 Norma LRI Hvy Palma 1/9-1/8
300 Norma LRI Hvy Palma1/9-1/8
338 Lapua LRI 1/10.5-1/9.5
338Lapua Factory
37xc LRI Heavy Palma 1/11-1/10
37xc Spartan Heavy Palma or Hvy Varmint 1/10
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So that was just some initial load testing at 100 yards but you can see it favored the heavier bullets. This was in a 300 norma and we were pushing the 220's to 2970 with 82gr of re26.
Got My 308 Shorty. Probably going to rattle can it. Overall I'm very impressed! 300 PRC barrel is on order, apparently its going to take 12-18 months
I want a 308 shorty as well. My problem is I have too many damn rifles and barrels to keep justifying more barrelsGot My 308 Shorty. Probably going to rattle can it. Overall I'm very impressed! 300 PRC barrel is on order, apparently its going to take 12-18 months
View attachment 8338248
How much does your rifle weigh as configured in the picture?
Always loved the short 17” rifles. I have the most fun shooting my 17” with my can. Dang, 10-12 months? Where did you order from, Barrett or elsewhere?Got My 308 Shorty. Probably going to rattle can it. Overall I'm very impressed! 300 PRC barrel is on order, apparently its going to take 12-18 months
View attachment 8338248
Just weight in at 16.5 lbs as configured, it’s basically a bull barrel under there so she’s got some heftI want a 308 shorty as well. My problem is I have too many damn rifles and barrels to keep justifying more barrels
How much does your rifle weigh as configured in the picture?
Accurate as all get out though, first round hits at 800 yards
The Canadian distributor for Barrett, dumb part is i can import the kit cheaper direct from the states and have it in three weeks… gotta love the supply chain….
I've been reading on the forum for quite a while now and have gained so much information from everyone on here. It really is one of the best resources out there for anything long range related. I finally figured I would reply with my MRAD and how it's set up. It's been a great gun so far and I've been able to shoot several hundred rounds out of each of my barrels.
Here is my current setup... Eager to hear some feedback on any changes y'all would make.
Currently have my Proof Research 7PRC barrel installed with an Unknown Munitions Ti Pro 5 brake. (I also have the Barrett .338 & 6.5 creedmoor barrels)
Recently picked up an Area 419 ARKALOCK rail to mount a bipod, Garmin Xero C1, and a Tri-Pod
Atlas CAL Bipod
MDT Grip
Spuhr Mount
Nightforce ATACR 7x35 F1 with Tremor 3 reticle
Vortex Impact 4000
Here is my current setup... Eager to hear some feedback on any changes y'all would make.
Currently have my Proof Research 7PRC barrel installed with an Unknown Munitions Ti Pro 5 brake. (I also have the Barrett .338 & 6.5 creedmoor barrels)
Recently picked up an Area 419 ARKALOCK rail to mount a bipod, Garmin Xero C1, and a Tri-Pod
Atlas CAL Bipod
MDT Grip
Spuhr Mount
Nightforce ATACR 7x35 F1 with Tremor 3 reticle
Vortex Impact 4000
Great setup! The Tremor3 is the sh#%! I just got the Vortex on sale at Europtic. My MRAD was pre-Mlok but I was still able to mount the Area 419 ARCA rail on it. Thinking of moving it forward as far as I can to get the bipod closer towards the muzzle for extra stability.
Yeah, this is my first optic with the Tremor3 reticle and I'm loving it. The ARCA rail is great! I'm looking forward to being able to use it with the Area 419 Garmin Xero mount. I'm curious if moving the ARCA rail out further would provide a benefit. I can see how it would provide a bit more stability but am curious if it would flex at all negating any stability benefit you would get from pushing it out further.
I think Frank covered this a few years ago. Cantilevering the Arca rail out in front of the stock or handguard introduces measurable inconsistency.
Thanks for clarifying. I figured that may be the case.
For whatever reason, want to see if I can get my MRAD down to <= 15lbs (without a bipod or sling). I’m thinking a 18-20” barrel, NX8 4-32x with a Spuhr mount, and an omega suppressor can do it.
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