Opinions on barrel length

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  • Last Post 05 September 2018
Scearcy posted this 11 August 2018

Good morning gents. No data required here - just opinions. I have a Savage Model 12 FTR (I believe). I bought it really cheap and thought I could make some money. Well not so much so it should make a really good test bed for some of the theories being discussed here. For those of you not familiar with this model it has a 30" heavy barrel and the Savage target action. Think of it as sort of over the counter Palma or F class rifle.

Here is my question. It is really muzzle heavy with the 30" barrel. If fact it is so heavy that I don't believe I could shoot it in the CBA Heavy class at a match. I am going to shorten the barrel. My question is what is the optimum length?

how-much-to-cut-off

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Larry Gibson posted this 05 September 2018

Frank is correct.  The bullet was designed to fit the throat of a 30-06 XCB reamer which has been used to chamber numerous rifles for 30 XCB (30x57), 30x60 XCB and the 30-06 XCB cartridges.  The bullet was designed to match the reamer's throat.  I do believe the reamer's throat was angled for cast bullets though I don't recall the specifics.  Goodsteel had the reamer made and has done the chambering so a check with him should get the exact information.

As to the 30 XCB design.  I have shot mine now in numerous factory and milsurp .308Ws and 30-06s, in my own 308 CBC and in the 30-30 cartridge in a 21" Contender barrel.  In every case exceptional cast bullet accuracy for each rifle was easily obtained and consistent regardless of the leade taper, type of rifling, etc.  The 30 XCB design has prove to be an exceptionally accurate cast bullet in my M70 .308W target rifle and my M1903A1 National Match rifle.  The M70 Target has a factory (Winchester) chamber/throat/leade and the M1903A1 NM chamber was finish reamed with a reamer made for M72 ammunition.

On a lark I also tried it in my 10" Contender 32 H&R and was surprised by the accuracy even though the velocity left a bit to be desired.

LMG 

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

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Scearcy posted this 05 September 2018

Gentlemen

This thread has drifted far afield. I apologize. But thanks to the GunDoc, a meaningful trip down memory lane, and everyones help with the mystery bullet, I had a great time.

After a lengthy affair with the 243, I intend to spend the next few months shooting new bullets through some long neglected 308s. I am not promising to further cast bullet science one single millimeter but I will share my experiences as I go. I should mention I have ordered a taper die from Mountain Molds as was recommended in this thread. I will shoot a lot of before and after being tapered groups. Perhaps that will answer some questions that have been posed lately.

Jim

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frnkeore posted this 05 September 2018

Sounds like they were trying to match the '06 throat at, 1.3713 deg, per side.

Frank

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45 2.1 posted this 05 September 2018

The taper is .011 inch in diameter over .221" in length according to NOE. Who has the math?

1.425618791 degrees per side = 1 degree 25 minutes 32 seconds approx. per side

 

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Scearcy posted this 05 September 2018

The taper is .011 inch in diameter over .221" in length according to NOE. Who has the math?

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45 2.1 posted this 04 September 2018

Length from .300 bore diameter to .3125 bearing surface is about .207" long...so taper is steeper than 1 degree. 

 

A little under 1.75 degrees per side.................. actual (per your dimensions) is 1 degree 43 minutes 46 seconds rounded to nearest second.

 

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OU812 posted this 04 September 2018

Length from .300 bore diameter to .3125 bearing surface is about .207" long...so taper is steeper than 1 degree. 

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Scearcy posted this 04 September 2018

Ken based on your numbers I believe the bullet tapers at 1 1/2 degree per side - same as a factory 308

Jim

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Ken Campbell Iowa posted this 04 September 2018

1 degree gives about 0.035 diameter difference per inch.  so if over a quarter inch 1 degree per side gives about 0.008-0.009 thou diameter difference.    normal chamber nomenclature refers to taper per side.

btw it takes a half degree per side taper to engrave a half inch of bullet BEFORE IT IS FIRED without smunching the bullet with a hammer ... so to speak.

note:  if you have a 1/4 degree throat ... you can engrave the full 1 inch of your bullet with little pressure BEFORE FIRING ...  is that breech seating ??  oh my golly ... could it be that easy ??  maybe the CBA R&D team should play with that .

see what i did there ??

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Scearcy posted this 04 September 2018

It appears to me that there are two distinct sections that are angled differently from each other. I do not have my own mold yet so that is about ll I can tell you. Dust off your trigonometry and calculate the angle from NOEs schematic. That should be close.

Jim

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OU812 posted this 04 September 2018

I have this mould and is probably my easiest mould to cast with. Bullets fall from mould very easily. NOE has made improvements such as elimenating raised parting vent line on tip of bullet.

BTW...what is the as cast angle of tapered section.

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Scearcy posted this 04 September 2018

Larry

Thank you. I figured that out last night when I found out who had supplied my sample  bullets. I have already ordered a mold this morning. The picture on the NOE site is a bit inaccurate but all is good.

I am going to test that bullet as well as a couple of others in 3-4 rifles over the coming months. Now that I know I can soon make more, I can shoot up my current supply.

Jim

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Larry Gibson posted this 04 September 2018

Scearcy

Your bullet appears to be the 30 XCB (NOE 310-165-FN).  The short radius ogive and multiple shallow lube grooves are my input into the design. It has proven to be an excellent design and is extremely accurate at various velocity levels.

LMG

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

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pat i. posted this 04 September 2018

Great advice Brodie. Every once in a while a name will pop into my head and put a smile on my face. Maybe it's age or internet or modern life in general but it seems things were a lot more fun back then. I don't remember people being so serious about something that's supposed to be a hobby or lacking a healthy dose of humor. 

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Brodie posted this 04 September 2018

 Yes it can be depressing.  It helps to remember all the good times you had with those and other people who have passed on.

B.E.Brickey

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Scearcy posted this 04 September 2018

I hear you, Pat.

Jim

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pat i. posted this 03 September 2018

Sorry to hear about Gerry he was a great guy. I was the Director of Registered Competition at the time those guys were all shooting and while it had nothing to do with me I still feel it was the high water mark of the CBA match program up to this point. A lot of experimenting. A lot of really good shooters. And a lot of laughing. I was up to Minnetonka a few times and always left smiling. Better get back to cast bullet stuff because talking about losing all those guys is depressing and making me feel old.

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Scearcy posted this 03 September 2018

I am sorry to say Gerry is gone too. He died not long after Dick. Sam Wosmek is still kicking. He shot the Regional when he was 90 years old. We have a good group of guys now but we can't shoot like that bunch could.

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pat i. posted this 03 September 2018

Dick was a great guy and we had a lot of cast bullet talks. Its a shame losing guys like him, Ed Doonan and Norm Duesterhoeft. I met a lot of great people playing this game. What about Gerry Barnes? Another guy I liked being around.

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Scearcy posted this 03 September 2018

I can't see much chance of it being anything else but LBT. No one else catalogues anything similar that I can find. I have reached out to the only other guys I know who use LBT molds. It could be tomorrow before I hear from them.

No this was after Dick's time. He was my mentor in all things cast while he was with us. His rifle disappeared. I have never seen it again. 

I reached out to a custom mold maker to see if they would do this type of project. They are quite responsive so I expect to hear from them tomorrow. I am concerned that it might be very difficult to get this mold on Verals to do list. 

Jim

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