Gunsmithing custom barrel questions

[lsm62]

i am going to have a barrel made chambered in 300 weatherby and was going to use a standard over all cartridge length (3.56) and set the refiling back to .005 off the lans with a 208 Amax. I now am thinking of using an overall cartridge length of 3.6 and setting off the lans .010.

other specs, heavy palma barrel 26 in long with a 1:10 twist on a mark v action.

any thoughts or suggestions would be appreciated.

Thanks lsm

 

[seanh]

Re: custom barrel questions

the only reason I see to have a longer OAL is to be able to add a bit more powder which is really not necessary with the proper load.

The reason most people go with a longer OAL is to get closer to the lands. If you're having a custom bbl made why not just have it set for factory OAL + .010? Now, you'll be able to use factory ammo and get decent accuracy

 

[doc76251]

Re: custom barrel questions

You would probably do a bit better to load an EMPTY round to the way you want it and sent it along with your order. The Gun plumber can chamber to your specs and ogive at that time.

Remember the OAL is restricted by the length of your magazine box, the ogive length is restricted by your chambering.

Cheers,

Doc

 

[lsm62]

Re: custom barrel questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: doc76251</div><div class="ubbcode-body">You would probably do a bit better to load an EMPTY round to the way you want it and sent it along with your order.</div></div>

yes the maker already requested that i do that. i just don't want to set it up for the standard COAL and find out that i limited myself on the powder side of things. i would like to get the 208 Amax as close to 3000fps as possible.

 

[eddieharren]

Re: custom barrel questions

Check out a chamber print for the SAAMI 300 Wby. chamber. I think you will answer a few of your questions right there. PY&G will FAX you a reamer print if you ask them. It will differ slightly from a chamber print but will still answer most of your questions.

 

[lsm62]

Re: custom barrel questions

Bump

 

[JFComfort]

Re: custom barrel questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: lsm62</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: doc76251</div><div class="ubbcode-body">You would probably do a bit better to load an EMPTY round to the way you want it and sent it along with your order.</div></div>

yes the maker already requested that i do that. i just don't want to set it up for the standard COAL and find out that i limited myself on the powder side of things. i would like to get the 208 Amax as close to 3000fps as possible.</div></div>

Getting a 208 going 3k was pretty easy with my .300 WM 700P 26" barrel 1-10" twist. The finial load ended up being 208 A-Max/FGMM Mag. primer/80 grs. Retumbo/COAL 3.62"

I think sending a dummy round with the action and barrel is a very good idea. Like someone else mentioned I would get a good measurement on how long of a round your magazine will accommodate then go from there. If you can run 3.62" or more I'd say you’re golden. From there the smith will have a better idea how much deeper he is going to set your headspace after accounting for bolt face clearance, thread/shoulder crush and bolt nose/bolt lug clearance.

Once you get the rifle back take a fired round that will chamber (headspace differences could cause hard bolt close) just barley kiss the neck with your re-sizing die then put in a bullet and chamber the case and bullet. If you get just the right amount of tension it should give you the OAL with the round pushed up against the lans. From there back them off for the amount of “jump” you want the get to loading and testing!

You can also have PTG make you a custom reamer. I’m not sure how much something like that runs.

 

[Texar2]

Re: custom barrel questions

I would go short and then rethroat it after a few thousand or loss of accuracy. Also consider how much contact you want between the bullet and the neck.