Ive ran arc, pmag, and accurate non binder without any problems. My biggest feed issues was with mdt non binder, I just tossed em back in the parts box. Those mags have only done okay with the 25cm. And still needed tuning.
- Thread starter Dthomas3523
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All four of my MDT 12 round mags feed reliably AS LONG as I only load 11 or less. 12 is just too tight. When running 6.5 CM, they were tight but would peel off that first round. The 6GT nose dives just below the feed ramp. I tried adjusting the mag latch (Matrix) but didn't really help. I'm just gonna run 11 rounds.
No mag mods. Factory.
No mag mods. Factory.
My one MDT is similar in that it's basically a 7-8 round mag. Feeds beautifully and smoothly up to that point, but nose dives with any more than that.
Has anyone had to turn necks on the Hornady brass??
Accurate-Mags work the best for me. Still needed to open/tune the feed lips up a bit in the front.
Both binder/less work. I find that the Binderless was easier to load full mag. Although I have 2 new ones and will find out if that's still the case.
MDT-12rnd mags work great, but will nose dive with when loaded full, even with opened front lips...my exp so far. Although, works fine with 6.5CM
Not on Hornady brass but I was forced to do it on 300 pieces of alpha brass.
I’ve heard of some having to do it on the earlier batches of Alpha (not the OCD) but not really needed on Hornady.
Had to? No. But I did clean them up, the variance was too much for my taste. Since then went to Alpha OCD, no issues.
Starting with new Hornady brass, I initially I tried a .267 bushing with no mandrel and felt the neck tension was just a little light for my taste. I tried a .266 with no mandrel and thought the tension was a bit too much. Settled on a .266 bushing with a .241 mandrel and like it a lot. Once I've fired all my brass I might change my mind. With no mandrel I'd choose the .267 bushing.
On the magazines, I use nothing but AI and have had zero issues with no tweaking required. Plus, the AI mags work in my other rifles, so no thoughts about changing anything.
On the magazines, I use nothing but AI and have had zero issues with no tweaking required. Plus, the AI mags work in my other rifles, so no thoughts about changing anything.
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Nope. My chamber will run Hornady and Alpha without issues.
I turned necks once, never again.
Have any of you guys had any luck shooting 107 or 110 smk’s or should i just stick with 108/109 bergers?
Sierra 107 SMK
Hornady GAP New Brass
34.5 grains H4350
CCI 400 Primers
First time Out of this...
Hornady GAP New Brass
34.5 grains H4350
CCI 400 Primers
First time Out of this...
107s will hammer 10-25 off lands 2900 H4350 2860 varget.
33.7 RL15.5. 108 berger @ .040 off lands. 2937 fps. 3 @ 100. Hornady brass, full prep. Truing at 970. It will do.
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108bt bergers shoot awesome! My last barrel shot stupid good with em, 35.5gr rl16 @ 2955 seated 10k off lands. Truth be told though for the prs game, a half moa group at distance vs a quarter moa group with a bullet with 15% higher BC equates to more impacts in the wind. I still have 2300 108s on the shelf and will use em eventually, but I switched to the 109. My new bra barrel might shoot the 108bt.
OK Final build spec is in with the smith - time to look for dies.
Whats the feedback on the RCBS MatchMaster Competition FL bushing die set?
Only other options I can find are a Wilson FL bushing sizing die or a used set of early version SAC dies.
Whats the feedback on the RCBS MatchMaster Competition FL bushing die set?
Only other options I can find are a Wilson FL bushing sizing die or a used set of early version SAC dies.
Dropped my load back to 32.5gr of RL-15.5 & 108 ELD'S. 3006 rounds down the standard stainless Bartlein now. I'll be running this load for the next PRS regional match.
I have the Matchmaster set, and really like them, the FL bushing die is fine, pretty standard, but I've really grown to like the micrometer seating die with the window. I paired them with a PMA expander die and Sinclair carbide mandrels, all in my LNL AP at the same time.... Don't know if it's right, but it's pretty easy and quick. That said, I don't have any Gucci dies to compare them too, all of my other dies are Redding, RCBS, Hornady and Lee (*gasp*).
I tried some RL16 under 109gr Hybrids and 112gr MBs last time out. It looks like my barrel seems to prefer 36.7gr with 112gr MBs .060 off. Also around 36.3gr with The 109gr warrants some exploration, I've loaded up a bunch of the 112gr load to run out to see how they do at long range. The 109gr were .060 off in these targets, I loaded a batch .04, .06, .08 and .1 off to see what shoots best.
This barrel has not seemed to be particularly consistent, I'm kind of tempted to pick up one of the new Proof pre-fits in GT to see if it is more consistent.
Also, for load testing I probably need to upgrade from my Bass Pro brand front bag, it's getting a bit long in the tooth with lots of stitching repairs to keep the hog trap corn I filled it with 10 years ago from leaking out, lol.
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Posting what I use, because data.
CCI 450
107 SMKs
36.0 gr h4350
0.050" Jump
Hornady Brass
2940 FPS
CCI 450
107 SMKs
36.0 gr h4350
0.050" Jump
Hornady Brass
2940 FPS
Is it just me or is the 6 GT a little on the finicky side? I’m on my first barrel coming from 6x47 and then dasher and decided to try this out as a middle ground between them. And alpha ocd brass available was a plus. Anyway I’m 650 rounds in after break in and load work up practice and a match.
I’ve found it difficult to really get a load I’m happy with especially with regards to consistency. I’ll get a load dialed in and shooting well and then load up more rounds and by the time I shoot them the groups have opened up. I’ve tried all the known pet loads and none seem to be really that good. Maybe I have a bad barrel but I know a couple other guys fighting same thing to find any consistency.
I’ve tried 4 bullets and two powders. I’m currently running 109’s at 2880. Alpha ocd brass, cci 450, n555 powder (very similar to rl16). I have also tried 4350 and saw no improvement. If I move seating depth .010 either direction it goes from .3-.5 moa on a good day to 1-1.25 which seems crazy that a rifle like this could shoot anything that poorly. 112 match burners and 105 jlks had 2-3 inch fliers it was crazy. I haven’t had to work this much to find and keep a load working in a long time. I’m not after bench rest accuracy but I want to find something I can take to a 2 day match 200-230 rounds and not question it.
Details on rifle and current load
Impact 737
Hawk hill 7.5 twist 26”
Manners tcs stock
Alpha brass 1x fired
109 Berger 1.930” base to ogive
2880 fps
VV N555 37.3 grains. According to my lab radar it takes 1 more grain 555 to equal 4350 velocity.
I have plenty of 4350 if powder is the main suspect but like I said I tried it and really didn’t see much improvement.
Any ideas? Anyone else see the inconsistency in this cartridge? I love my 22gt that thing hammers and took 20 rounds to find a solid load but the 6mm big brother seems not so easy.
I’ve found it difficult to really get a load I’m happy with especially with regards to consistency. I’ll get a load dialed in and shooting well and then load up more rounds and by the time I shoot them the groups have opened up. I’ve tried all the known pet loads and none seem to be really that good. Maybe I have a bad barrel but I know a couple other guys fighting same thing to find any consistency.
I’ve tried 4 bullets and two powders. I’m currently running 109’s at 2880. Alpha ocd brass, cci 450, n555 powder (very similar to rl16). I have also tried 4350 and saw no improvement. If I move seating depth .010 either direction it goes from .3-.5 moa on a good day to 1-1.25 which seems crazy that a rifle like this could shoot anything that poorly. 112 match burners and 105 jlks had 2-3 inch fliers it was crazy. I haven’t had to work this much to find and keep a load working in a long time. I’m not after bench rest accuracy but I want to find something I can take to a 2 day match 200-230 rounds and not question it.
Details on rifle and current load
Impact 737
Hawk hill 7.5 twist 26”
Manners tcs stock
Alpha brass 1x fired
109 Berger 1.930” base to ogive
2880 fps
VV N555 37.3 grains. According to my lab radar it takes 1 more grain 555 to equal 4350 velocity.
I have plenty of 4350 if powder is the main suspect but like I said I tried it and really didn’t see much improvement.
Any ideas? Anyone else see the inconsistency in this cartridge? I love my 22gt that thing hammers and took 20 rounds to find a solid load but the 6mm big brother seems not so easy.
Not I.
I loaded 36g of H4350 under a 107 SMK and three of the four groups were sub half MOA @ 100 yards.
Loaded up some 112 MBs at the same charge and similar results.
I think the powder is too slow for the GT. I am running 33.6 of RL15.5 and getting 2930 with 108 BT in 26" Bartlien gain twist. I think the GT runs better with a faster burning powder.
That’s interesting since 22 gt seems like slow powder like rl26 is working well. I like the case fill of the 555 better than 4350 and haven’t tried varget but I can, just seemed like I’d have a lot of empty case. I’m not having any trouble getting same velocity as the 4350 loads I see. I’ll do some more testing on varget and 4350 and see what I find. Although I’m growing weary of burning hard to find components!
Verget or H4350 with 109's is a perfect combination. Varget being the first choice.
Find your speed, jump them 60 and hammer down.
Should print in the 300's with a single digit SD without much brain damage.
Find your speed, jump them 60 and hammer down.
Should print in the 300's with a single digit SD without much brain damage.
No. In fact GT is actually the easiest thing I’ve ever loaded for. The 3 powders I tried were Varget, H4350, and RL16. All 3 powders worked well. Have you checked your barrel for a carbon ring? I’ve been through 3 barrels now and every one of them got a carbon ring right around 450-500 rounds. That may explain why you have flyers at the end of the ammo you have loaded. Could be that your cleaning and only getting a little of that ring out so it shoots normal for a bit and then opens up again. Just something to consider.
My experience has been kind of like yours with my particular rifle. I assume it's the barrel, or some other variable as opposed to the cartridge design itself, but the "pick a speed and load them up" cliche has not been the case for me. I've developed loads for a lot of rifles, and this one has just been kind of a pain, with some dead ends that looked good and then blew up later without a clearly discernable reason, finicky is a good word for it. Anyway, the real solution is probably to get another barrel, and not waste a bunch of time on StaBall next time around (although I've also tried Varget, AR-Comp and RL16, with the latter performing the best).
I can empathize, I've struggled with cartridges everyone else claimed were easy. I think H4350 is the ideal powder for 6GT but Varget (and equivalents) carried over from BRA shooters.
Weather wasn’t ideal but I went out and tested varget today after getting a few responses like this. Ran some 5 shot groups and a ladder 32.8-34.6 in .2 increments on paper at 100 with 109. Wind was 15-20 so no way was I gonna get much for consistency at distance on paper. I immediately noticed better groups at 100, and although my SD wasn’t bad before at 7 on average, every group I shot today outside the ladder was 3’s. I had more bullets touching or making ragged holes than anything I’d run in gt yet.
33.0 at 2850 just to start out looked pretty decent.
Ladder highlighted velocity’s I wanted to target
33.3 at 2875-2880
34.0 at 2920-2925
Loaded up 5 of each and both shot in the .4’s with SD of 3 and 3.1 with Virgin ocd brass. I was content with that considering the wind. Will be working on this more later this week, just gotta decide which speed I want to run the way it looks now.
Interesting side note the 2880 is where I’d been with N555 and I’m still at same seating depth of 60 jump. So I guess burn rate has something to do with accuracy even if you match speed and jump.
Scrubbed my bore with JB Paste in preparation for an upcoming regional match next weekend and sent ten down the bore today to add some fouling. I got caught in a down pour for the last 6 and was running the bolt fast but I'm happy with the results
round count as of today 3116.
round count as of today 3116. Last edited:
Switching from a shilen running 105 hybrids at 3010 with 34g of varget to a bartlein running Berger 108s or 109s.
Ran 2 ladder tests with each and both shot 33.7 really well both around 2880. One of the 5 shot groups with the 108s had an Es of 2. So I’m not complaining but to be honest I’m kind of surprised at the speed difference. With .3 less powder and 3-4 extra grains of bullet I’m losing 130fps. I ran one of the ladder tests up to 34.6gr and got up around 2950. Absolutely no pressure but seemed on the high side for powder.
I hadn’t planned on running this barrel as hot as the last one but it seems I’m going to have to run almost the same amount of powder.
Ran 2 ladder tests with each and both shot 33.7 really well both around 2880. One of the 5 shot groups with the 108s had an Es of 2. So I’m not complaining but to be honest I’m kind of surprised at the speed difference. With .3 less powder and 3-4 extra grains of bullet I’m losing 130fps. I ran one of the ladder tests up to 34.6gr and got up around 2950. Absolutely no pressure but seemed on the high side for powder.
I hadn’t planned on running this barrel as hot as the last one but it seems I’m going to have to run almost the same amount of powder.
2880 is a good speed for the heavier bullets. No need to try and push them to 3k.
Where are you going in such a hurry?
33.6g of Varget under a 105 hybrid runs 2885 with an SD of 4 or so. It's about a 2.5g wide node in my rifle.
No reason to pile powder on top when you have a node in the high 2800's IMO.
I ran the 105s at 3010 with 34gr of powder. Just seemed like I was Loosing a lot of velocity and using almost the same powder. And the bullet is only marginally heavier. I have no problem running at 2880 it just seemed slow for the powder amount but I guess not.
That being said I’ve shot a couple different tests and my graphs show a flat node for velocity between 33.7-33.9 but 33.8 hasn’t been grouping quite as well as 33.7 or 33.9. Also 33.7 had an Es of about 11 across 9 shots over two different days. But I’ve always tried to run in the middle of a velocity to powder node. 33.7 seems on the edge but has definitely shot the best at 100. Haven’t run them out to any distance yet.
That being said I’ve shot a couple different tests and my graphs show a flat node for velocity between 33.7-33.9 but 33.8 hasn’t been grouping quite as well as 33.7 or 33.9. Also 33.7 had an Es of about 11 across 9 shots over two different days. But I’ve always tried to run in the middle of a velocity to powder node. 33.7 seems on the edge but has definitely shot the best at 100. Haven’t run them out to any distance yet.
You’re also switching barrel maker as well which has an effect.
Here are 2 different ladders with some additional 5 shot groups at 33.7 and 34 gr from a previous day. Thinking about loading up 33.7 for the 108s and 33.7 and 33.9 for the 109s and just shooting groups with those 2. Leaning 33.7 for both but will take any input. All of those 5 shots groups were shot with a magneeto speed on the barrel and one of the days had very heavy mirage so I’m not taking those groups as gospel because they definitely weren’t my best, but 33.7 and 33.9 both grouped well
I've worked up a load using H4350, Alpha OCD, 450s, and Berger 108s.
I have Varget and 109s as well and looking to work a load for the 109s using both Varget and H4350 using the same brass and primers mentioned above. Starting point?
Thanks in advance.
I have Varget and 109s as well and looking to work a load for the 109s using both Varget and H4350 using the same brass and primers mentioned above. Starting point?
Thanks in advance.
Haven’t tried h4350. With varget I started at 31.5 and worked up to 34.6 and never hit pressure. Ymmv
Also used alpha ocd and 450s
Also used alpha ocd and 450s
I just worked my load up today with those.
24” Bartlein 7.5 twist. Berger 109 hybrids. Alpha brass, CCI 450’s and Varget. 33.4 gives me 2855 with an SD of 4-6
I settled at 33.7 of varget with both the 108s and 109s both around 2890.
Use the same load for 109's as 108's. Sell the Varget or use for something else.
Anyone have a lead on 8208 XBR charges behind the 105/107s? Hogdgon lists the Dasher with 107 SMKs up to 30.2gr of XBR for 2840ish FPS. I'm not looking for a fast load (my GT does 2980 with 36.0 h4350 already). I'm looking for a node in the 2700-2850 range.
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Anywhere from 33.0 to 34.0 varget. Should be in the 2800-2950 area depending on charge weight and lot of powder.
... and barrel length.
Any one shoot some 109 bergers next to some 109 eldm's? I am almost out of 108 bergers and keep hearing good feedback on the eldm's.
current load is
26" hawk hill 1-7.5
108 berger match
36.8g h4350
alpha ocd brass
cci 450 primers
CBTO 2.01
2950fps
with 33.4g varget i was getting 2895fps
current load is
26" hawk hill 1-7.5
108 berger match
36.8g h4350
alpha ocd brass
cci 450 primers
CBTO 2.01
2950fps
with 33.4g varget i was getting 2895fps
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As far as I know, unless some early testers or insiders, the only 109 eldm in circulation is with the factory ammo.
The actual bullets haven’t started shipping yet AFAIK.
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They are tough to find.
108’s are much easier. I’d also imagine the 109 Hornady will be easier once they are shipping.
