GTA
All Springer/NP/PCP Air Gun Discussion General => Projectiles => Boolit and Pellet Casting => Topic started by: Hobbyman2007 on April 27, 2019, 07:12:31 AM
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Looking for some advise here and hope this helps others . Looking at the barrel list TJ’s has I’m finding it hard to chose for a bullet shooter . I have a variety of bullet moulds from .220 to .225 and would like to have the best chance at accuracy with them . Right now I’m leaning towards the .22 in 1/2” OD with .218/ .222 in 1:16 “ twist .
What would you recommend and why , I’m open to other barrels makers also .
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LW makes good barrels and locally .224s are often on sale in 12" or 12.7" twist. 24" is enough for 100 fpe. Comparing TJs and LW I'd have to say LW has much smoother bore.
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I would check with JSAR, WAR or Mountain Air. They all offer barrels and should be able to help you out.
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I use the 14" twist TJ's with a 0.224" groove diameter (I think it's 0.219" lands)…. for bullets up to the length of the Aresenal 47 gr. "Bowman".... For longer, heavier bullets, I have one in a 9" twist, but Mike also makes a 12" I believe....
I know that the guys in Holland using the RWS 41.3 gr. swaged bullet (.22 LR copy) for 100 M benchrest found that a 16" twist barrel didn't cut it at over 1000 fps, which is what they run (mid 1000's)…. They use a 15" minimum, and most use the 14" Hornet barrel, which is what Mike's 14" twist is....
Other than a few airgun bullets, almost all the cast bullets you will find in .22 cal are 0.224-0.226", which may mean 2-step sizing to use in a 0.222" barrel.... JMO....
Bob
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Having both Walther barrels which are button rifled, and TJ's I don't know that I would say that Walthers are smother bores than the TJ's. But then again. I don't have any Walther PB barrels. Perhaps they are different.
I do know that Hammer forged, which are what TJ's are can be incredibly smooth. just look at he older BSA barrels with the rounded lands as an example. Incredibly accurate!
I lap all my barrels, so they end up smooth no matter what method was used. I do know that the TJ's are much harder barrels of Chrome Molly than a Walther AG. barrel. Again, talking Walther AG barrels.
Walthers have won many an Air gun (Pellet)Match. However, I don't know of them being used in any AG bullet shooting matches. I have one I am casting for now, and it is accurate. But not as accurate as the TJ.
The TJ's have been used in a number of matches now ,a dn recently swept the Extreme Big Bore event in AAA AG, as well as the very credible results from Dyotat100/Doug Noble.
There are custom PB barrel makers aplenty. The sky is the limit on both quality, and cost.
Knife/Mike
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Thanks for the info guys . The rifle I’m using is the K550 Evanix and I have it shooting at peak of 75 fpe with some 39 grainers . I capable of lowering the speed to whatever I want using a buffer between the exposed hammer and valve . The twist rate as I measured is 1:15 “ +/- 1” . That is pretty much right in the middle of the curve as far as 22 cal twist rates go so I don’t think that is a problem . I was thinking of replacing the barrel but it will shoot pellets so well anywhere below 1000fps I just can’t justify it . Looks like I need to work on both my casting skills and sizing . My testing methods are as follows , size 40 to 50 bullets from 3 different molds to the same size , go out and shoot . Come home , size another pile of bullets at a different size , go out and shoot those . Put all the reject sizes back in the pot only to cast them over again and repeating the process. You can see there a few flaws in my approach . I’ve got a mobile sizing press ready to bring to the bench with every .22 sizer from NOE . Now I just need to work on one bullet at a time . Again thanks for the info . The search for the ultimate .22 bullet / gun combo continues .
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Just finished watching one of Matt Dubers videos on the FX impact X slug liners and he brought up a good point. I now remember one of Tom Costons posts that also mentioned this . Shooting slugs needs to have some greater distances to see how they actually perform . I’ve been shooting between 25 and 35 yards , and only stretching them out to 70 and beyond if they did well enough . To be honest I’ve only shot one bullet out past 70 in the .22 cal . Where as my .257 only started at 100 with stellar results . Going to stretch the bullets out to 75 yards as my new starting point from now on . I saw some similar results when testing the 51 grain BBT bullets as I was testing at 30 and 50 yards .
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Matt is right on the money here. As RC pointed out years ago, it sometimes takes some distance for bullets to "go to sleep", and then go on to fully stabilize and give great performance. ;)
Mike
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Just finished watching one of Matt Dubers videos on the FX impact X slug liners and he brought up a good point. I now remember one of Tom Costons posts that also mentioned this . Shooting slugs needs to have some greater distances to see how they actually perform . I’ve been shooting between 25 and 35 yards , and only stretching them out to 70 and beyond if they did well enough . To be honest I’ve only shot one bullet out past 70 in the .22 cal . Where as my .257 only started at 100 with stellar results . Going to stretch the bullets out to 75 yards as my new starting point from now on . I saw some similar results when testing the 51 grain BBT bullets as I was testing at 30 and 50 yards .
I just watched that same video today and really makes me wonder how slugs would have done on the guns out past 55yds....that's the farthest I've ever shot slugs :o like you I guess I need to stretch them out 75-100yds minimum before I decide what there like. Man makes me wonder all my guns I've had before that could have probably shot slugs very well ::)
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That's all well and good, but what if your target is only 50 yards out. It really doesn't matter if they straighten up beyond that.
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That's true Keith but really I'm thinking about like 2/3"-1" groups at 55yds max. Ive had quite a few do that well consistently. But both Matt and Tom said that they've seen slugs do ok at 50yds and then hold that tight or better out to 100yds. Now if there shotgunning that's a no go obviously but I think if there's some promise it's worth stretching out to see.
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If I would see a group that opens up to 1” at less than 50 yards I would pass and move on . If they stay at the same or better at 100 I would say their keepers .
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Issue can also be harmonics. Now for our little test! ;)