MORE TWIST

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  • Last Post 22 August 2018
joeb33050 posted this 30 July 2018

Just back from the range, M110 Savage barrel, Hornady 55 gr fmjbt cannelure;

7/Titegroup, 5 shots in 7"

8.5/Titegroup, 5 shots in 4.75"

and NO tipping.

This twist/stability business gets stranger the more I shoot. 

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pat i. posted this 22 August 2018

Larry I'm chasing pb bullets in fixed ammo and smooth bore trade guns in muzzleloaders at the moment so will probably never get around to testing the 311299.I don't even own the mold and have no interest in getting one.

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Larry Gibson posted this 22 August 2018

"Stability doesn't guarentee accuracy."

pat

No it doesn't.  As I mentioned my testing was limited.  The testing was done with one powder pushing it hard as I was asked; how it would do in the 2400 = 2500 fps range.  I quickly found it was fine for "hunting accuracy" giving 1 1/2 - 2 moa accuracy in that velocity range with the one powder.  The person I ran the test for was satisfied with that so I didn't test any further as I had no intention of using it for any CBA competition as the 311466 and 30 XCB were proving excellent in my Palma rifle. 

Apparently competition accuracy is your interest?  Only way you'll know if it meets your "accuracy" requirements is to try it?  Be interesting to see the results. 

LMG

Concealment is not cover.........

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pat i. posted this 22 August 2018

Frank so you haven't shot the RCBS 200 Sil. I haven't either but was just passing along what I've heard and read. Maybe it had nothing to do with the design itself but with the dimensions the mold cast.

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frnkeore posted this 22 August 2018

Pat,

Since the RCBS is a GC bullet, I can't shoot it in competition but, I have shot the NEI 168 308 PB (2 bands and a long bore riding nose) that is 1.19 long in my 14 twist Douglas barrel. I have shot 1 1/4, five shot groups with it @ 200 yds. I believe that shows it's stable and accurate. The bullet that I shot the most, before going to my 33 cal rifle, is a tapered, .310 - .305, spitzer bullet that is 1.165 long.

Starting in June, I have now gone back to 30 cal, 13 twist barrel and have started shooting a bullet 1.30 long, that is accurate. I got 2nd place at my Spokane match with it. It tips slightly but, I will shorten the base band by .025 and that will stop that. I've got a lot more development work to do on this rifle but, it's starting to produce results.

I've been shooting in ASSRA competition, since 1985 and I always shoot the longest bullet, that will stabilize in the twist rate that I use. Some people in my discipline, shoot over stabilized bullets and do well but, I think that any RPM, over what it takes to stabilize a bullet, is wasted.

Frank

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pat i. posted this 22 August 2018

Stability doesn't guarentee accuracy.

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Larry Gibson posted this 22 August 2018

Not the RCBS Sil Bullet but I have some experience with the 311299 in my 14" Palma rifle.  Didn't do a lot of load development with it but did determine that it will stabilize fine in the 14" twist. 

LMG

Concealment is not cover.........

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pat i. posted this 22 August 2018

Were talking about a 14 twist barrel and have you or anyone you know shot the 200 sil bullet?

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frnkeore posted this 22 August 2018

I posted the above, in responding to Pat I's post. I had missed this thread, as it started when I was in Spokane, attending a 2 week shoot.

I've read most of it now and will hopefully answer some of the questions.

1. The 25 ring in a ASSRA, 200 yard target is 1.50". Most 250's create a 1 - 1.25" group. Our 5 shot group record is .275 and 10 shot, .924. I have seen 10 shot score groups, in the 7/8 range but, they don't qualify for group records, of course.

2. There are basically three reasons that ASSRA and ISSA scores have improved in the last 15 years. The first is barrel design and quality. Although there have been other barrels that have shot 250's, Douglas and Pac-Nor being two, the RKS, choked, gain twist, far exceeds them. BTW, Dale Reynolds, shot four 250's and one 249 (1249/1250) in a ISSA , 50 shot match, with a Pac-Nor barrel but, neither he or no one else has matched or exceed it but, there are a lot of ISSA, 50 shot scores in the 1240 - 1245 range at the annual match at Raton, NM.

1. Barrel

2. Shooter skill and attention to detail and wind reading ability

3. Breech seated bullet design

Our bullets won't help CBA fixed ammo guys improve their scores though.

To answer JoeB's, bullet fit question. The taper of the bullet, usually on the front driving band or bands, must fit the taper of the throat and if it has a bore riding portion, it must contact the lands of the rifling as a basic start. It will help, if the base band fits any freebore that the chamber has, while still being in contact with the ID of the case mouth and that case mouth be chamber size on the OD, to to guide the bullet to battery.

Frank

 

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frnkeore posted this 22 August 2018

I've never tried the 200 gr sil bullet and will be made a liar by someone as soon as I post this but best as my memory serves me I've never heard of anyone who had any luck with that bullet.
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I'm not sure what you referencing, regarding the RCBS, 200 gr Sil but, if it's a longer bullet, not not being as accurate as a shorter one. The Egan, MX 4 30 ARD, most likely holds more CBA records than any other. It is 1.25 long w/o the GC and about 1.265 long, with it. It is usually used in a 10 - 11 twist barrel but, will be well stabilized in a 12 twist.
It's also, made with a 1 deg per side taper, on the forward driving band, to match a 1 deg per side throat and uses a .45 long, .301 bore riding nose.
While I can't say that I've seen the 200 gr RCBS win a CBA match, I have seen it place well. It is designed, something like the Egan at 1.175 long w/o GC. It has a tapered forward driving band at a angle of .586, per side, with a much shorter .110 long x .301 bore riding section.
They are both designed with a .309 base band but, many had the base band made on their Egan's at .311 - 314.
The RCBS can be stabilized in a 14 - 13 twist barrel and if the throat for a RCBS were cut at .586 deg, I see no reason that it couldn't preform as well as the Egan.
There is no magic in cast bullets. The magic comes from attention to detail and the bullet fit, to the throat.
Frank

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pat i. posted this 22 August 2018

I've never tried the 200 gr sil bullet and will be made a liar by someone as soon as I post this but best as my memory serves me I've never heard of anyone who had any luck with that bullet.

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Ross Smith posted this 22 August 2018

I was going by advice based on success for the lyman 311299 which is a 200+-gr. have no idea on length. Went thru the same thing on my 32-40 douglas 1-14. The old 165 shoots better than the newer 200grn. Same thing 1" or less.

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pat i. posted this 22 August 2018

Cast works just like jacketed. Slow twist shorter bullet. I saw you ordered a 14 twist Douglas barrel. I always had good luck with the RCBS 165 Sil in a 1 1/2 degree included angle throat. If I remember right it's 1.020. When I made my taper die I switched to a LBT spitzer the same length as the Sil bullet. I know you're just saying weight as a replacement for length but forget all about weight, length is what matters. In fact I've wished for a long time mold manufacturers that don't provide a print would drop weight and replace it with length although RCBS 1.020 Sil doesn't sound as cool.

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Ross Smith posted this 22 August 2018

Okay ya'll: This is half question and half observation. It seems that with jacketed bullets the faster the twist the heavier(longer) the bullet will stabilize. The slower twist, the lighter the bullet. Now, in the cast world, slow twist is best for heavier bullets????????

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Ed Harris posted this 21 August 2018

This bullet is cut by Accurate to fit a pound cast of a No.4 Mk1* .303 Long Branch Enfield.

I ordered the mold at +0.002 from this print, because my rifle is .316+ and the resulting bullets "fit" mine, not marking the bullet in chambering, but obviously squeezing the coating of Lee Liquid Alox off to show a shiny bullet where the lube was.

 

 

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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joeb33050 posted this 05 August 2018

What fits the throat, how to fit a bullet to the throat or what a throat is? I do know the first two quite well........ and have some bullet designs made by MP Molds that some people rave over. There are enough different illustrations of what things ahead of the chamber are called to confuse most anyone. I for one don't care what you call those items..... I only care about accuracy and performance. You haven't believed the easier to do stuff yet, so the more advanced stuff is out of your comprehension. Let's just leave it at that!

 

You're now officially the 67th person in a row who can't explain/draw "The bullet must fit the throat.". What's that buzzing? Is it my BS detector?

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45 2.1 posted this 04 August 2018

What fits the throat, how to fit a bullet to the throat or what a throat is? I do know the first two quite well........ and have some bullet designs made by MP Molds that some people rave over. There are enough different illustrations of what things ahead of the chamber are called to confuse most anyone. I for one don't care what you call those items..... I only care about accuracy and performance. You haven't believed the easier to do stuff yet, so the more advanced stuff is out of your comprehension. Let's just leave it at that!

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pat i. posted this 04 August 2018

LOL!!!

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joeb33050 posted this 04 August 2018

45, I just want to know what the throat is, and the bullet dimensions are to make "the bullet fit the throat". If you don't like 308, pick another ctg. Don't be the 67th person in a row to not explain. Should be easy for a wizard like you.

 

Joe, the lead throat slug dimensions encompass the throat area in the barrel, that is they show the dimensions of the throat....however the manufacturer defined them or the throat wear after shooting it for a while. Your rifle probably doesn't match my rifle or somebody else's rifle, same as fired cases out of one chamber not going in another chamber. The dimensions do allow one to fit/check/design a bullet to that rifle though. If a bullet goes in and doesn't touch the right places, then it is undersize and will perform the 1 MOA to 3 MOA normal groups you see. You asked for WHY?....... it's to get you below the normal "why can't we do better" groups you and others put up.

 

You elusive rascal, you don't know, do you?

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45 2.1 posted this 04 August 2018

45, I just want to know what the throat is, and the bullet dimensions are to make "the bullet fit the throat". If you don't like 308, pick another ctg. Don't be the 67th person in a row to not explain. Should be easy for a wizard like you.

 

Joe, the lead throat slug dimensions encompass the throat area in the barrel, that is they show the dimensions of the throat....however the manufacturer defined them or the throat wear after shooting it for a while. Your rifle probably doesn't match my rifle or somebody else's rifle, same as fired cases out of one chamber not going in another chamber. The dimensions do allow one to fit/check/design a bullet to that rifle though. If a bullet goes in and doesn't touch the right places, then it is undersize and will perform the 1 MOA to 3 MOA normal groups you see. You asked for WHY?....... it's to get you below the normal "why can't we do better" groups you and others put up.

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joeb33050 posted this 04 August 2018

Joe, you''re Hopeless........................ Frank Marshall, Jr. and many others knew throats wear and advance. A rifles throat doesn't stay in SAAMI condition very long, nor do the tolerances match what they say they do either with all the manufacturers out there. Taking the direction you seem to be going, you're not going to solve much of anything, but Good Luck to you anyway.

 

45, I just want to know what the throat is, and the bullet dimensions are to make "the bullet fit the throat". If you don't like 308, pick another ctg. Don't be the 67th person in a row to not explain. Should be easy for a wizard like you.

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