If its worth anything, I asked recently on one of their Instagram posts if it was in fact an 8 twist, and they said yes it was.A custom will be a couple thousand more than the MPR. Does that rifle really come with an 8 twist barrel?
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If its worth anything, I asked recently on one of their Instagram posts if it was in fact an 8 twist, and they said yes it was.A custom will be a couple thousand more than the MPR. Does that rifle really come with an 8 twist barrel?
Looks like I'll start with focusing on MPRprobably 4K if you get fluting, cerakote, etc.
Thinking that's too quick? I do see most others are around 9.A custom will be a couple thousand more than the MPR. Does that rifle really come with an 8 twist barrel?
To guys shooting 300 Norma, what is real world barrel life for the 300 Norma, in a target shooting environment, quicker strings. How close is this cart. Design to the 300Lapua or 30-338 whatever you want to call it. Thanks
How much a gain in velocity the NM actually has over the WinMag with the same barrel length and same bullet weight?
I called sierra and they told me their new (LONG) 230s required 8 twist as bullet being longer than 230hybrids not much longer..one of my 300nm has 9 twist shot that 230mk no issues at all besides asking for CIP length mags
What freebore youre using mine touching land where 2/3 of neck is on bullet secant..
230 smk
Im guessing with 215 the bullet not contacting whole neck of the case while its 3.700? Im just trying to see what freebore would be good for matchkingNot 100% on freebore I bought barrel used for my AXMC. It was chambered by APA for the 215 berger. OAL is 3.700" at the lands so I ended up with a 3.685" OAL to start out with.
Im guessing with 215 the bullet not contacting whole neck of the case while its 3.700? Im just trying to see what freebore would be good for matchking
What is ballpark for custom building with the Deviant w/ Bartlein custom?
Round 2 with the 230 Sierra today using retumbo made it past the 3000 fps mark on lab radar but pretty good crater on primer. Really nice wide node at 2945 fps and amazing accuracy so I’m gonna load up 20 of them and move out further.
Shot the 198 Flatline load at 1360 & 1580 while I was out. Needed .1 more elevation from AB call but was on the plate with both. Spotting hits and misses at 1500+ is challenging with this bullet for sure! Magneto speed impact indicator was a huge benefit! first time using one.
I’m waiting on the same barrel and am planning on using the Flatline 198s. Would you care to share some information on your load?
Running 84 grains RL26 at 3.765 OAL jumping a long ways I’m sure it was freebore set for 230’s based on my 230 OAL. I ran ladder up to 85.3 where I saw pressure. 84 gets me 3145 SD of 6 and 3/8 accuracy. Had it to 1580 so far and they get there quick. Cci 250 and Norma brass
Thanks for that. I’ll start lower and work up. This will save me time and money, so thanks again!
Has anyone used a gain twist? Talked to Bartlien and Sierra about the 230 Matchking. Looking at 8.5 - 8 maybe. 27 - 28 inch barrel
If it’s not broke don’t fix it maybe? Had read about gain twist barrels years ago but never gave them much thought. Theory seems sound when your target distances start at 1000yd and end North of 2500 yds give or take. 1:8 seems fast when that is what I have for a 6.5 Cm and a 6.5 Gap 4S. Don’t want to deal with solids so I don’t want to over spin either! It was recommended to not spin up over maybe a 1/2” on this. The bullet will be regroving all the way down the barrel on the gain twist. Maybe increased jacket damage, or is it less damage due to not starting so fast?Running a straight 9 twist with good results on 230 Sierra now. My next one might be a gain start at 9 finish at 8 or 8.25 but part of me says stay with what is working.
If it’s not broke don’t fix it maybe? Had read about gain twist barrels years ago but never gave them much thought. Theory seems sound when your target distances start at 1000yd and end North of 2500 yds give or take. 1:8 seems fast when that is what I have for a 6.5 Cm and a 6.5 Gap 4S. Don’t want to deal with solids so I don’t want to over spin either! It was recommended to not spin up over maybe a 1/2” on this. The bullet will be regroving all the way down the barrel on the gain twist. Maybe increased jacket damage, or is it less damage due to not starting so fast?
That’s about the velocity I hope to get. Are you using Retumbo? Maybe a 9-8.5 is what I should consider. Makes sense that the faster you try to spin the more pressure you build. I have very little experience at that Mile plus range but research says there will be some Benifit of a few more rpms to reach that extreme yardage. I have searched for anyone using gain twist on the 300NM but come up empty. I see 1:8, 1:9, & 1:10. Not very many complaints about any of them? Not sure on the ranges those are shot at. A good spin at 1200 might fall apart at 2200 with the longer projectiles!I worry about going faster twist not getting the velocity before pressure. I know some folks smarter than me might argue and prove me wrong but seems like forcing a bullet down a bore of equal length forcing one to spin 200k rpm vs 250k (pulled numbers out of thin air for hypothetical ) would take more effort and therefore create more pressure. I know gain twist should help ramp it up more gradual so maybe the goal should be to average 9 in my case like a 9.25 to 8.75 but then have I really gained anything? In my 28” 9 twist I broke 3000 fps with the 230 and settled on 2950 accuracy. The more I think about it the more I should probably just get a 9 twist on order this summer.
I have seen a few statements on a 30 and 40 deg improvements on this round. How much do you think that buys you? Does your ballistic data hold true and predictable out to 2300 at least? Will it still shoot factory decent at all? I hadn’t considered the improved version until just recently. I have just about talked myself into a 28” Bartlein with a 1:9 - 1:8.5. When I burn that one out if I feel the need I can go 1:8.5 - 1:8.0 maybe.Since smk demand 8 twist for their new 230,which i really think way too fast..but ill try 9.25-8.50 gain twist and see what will happen..im pushing them with 1.9 bartlein 30" now 3100 fps no problem with my 30° improved with RETUMBO.. I might try rl50 since its more stable than rl33
I wish someone could fire some bullets with varying twist rates and speeds in a water tank so the physical damage to them could be analyzed and compared. I suspect if they did, there would be something there?
This would be an interesting experiment to perform as it would likely entail firing into a pond or lake at significant distance, then recovering the projectiles. Firing into water at close distance often damages the projectiles and would invalidate your results. Check out the Mythbusters episode where they were shooting into a pool point blank.
Other than that, you are largely asking a question that I asked here years ago which was what effect various types of rifling had on external ballistics. No one had much of an answer.
I am going to go out on a limb here, as I am by no means an expert on this subject, but hopefully it will get the conversation started, and maybe some more qualified experts will jump in.
8<
Talking to Bryan Litz, he stated this should NOT be an issue with a "properly designed bullet" in a "reasonable twist rate" fired at an "appropriate speed". The key then becomes defining:
"Properly Designed Bullet" - this comes down to the jacket being strong enough, and the jacket and core maintaining their stability. It is a well known fact that a thin jacket bullet can be "blown up" by firing them out of a fast twist rate barrel at very high velocities.
"Reasonable Twist Rate" - I have no idea on this one? I am not sure if going from something like a 10 twist to an 8 twist in some situations could be enough of a change to produce negative consequences? The impact of this variable would obviously be heavily tied into the influence of the other 2 variables.
"Appropriate Speed" - I would normally say this could come into play if it is above 3,000 fps, but I am once again not really sure of the answer?
8<
Hi,
@LRShooter101
Can you please turn your post on this subject into it's own thread?
Not many members read this thread due to OPs anti-USA post in other sections of the hide.
Sincerely,
Theis
I have had the same results. The 225 eldms really like the 1:10 twist barrel.I have a 9-twist 27" Bartlien that shoots the 230's at 2970fps. I'm at 900ft elv. I've tried to shoot the 225 ELD-M's in two different 9-twist barrels and they don't seem to like that fast of twist rate. However, they shot lights out in a 10-twist. For me, the 300NM is a step up from the 338LM in terms of shootability and accuracy. In my opinion brass has been the achellies heel of the 300NM. But Peterson and Lapua have solved that issue.
In the years since writing that article, as the chief ballistician for Berger, he’s gotten them to produce bullets that fix the problems he wrote about in that article.
Can you post a link about this? How did they fix it? What bullets did they make to compensate the issues ?