30BR Reamer Specs

[gzig5]

I am putting together a hunting rifle on a mini-Mauser action in 30BR. It will need to feed from the magazine. It will use 110-150 grain bullets at a COL of about 2.300". Does there exist a no-turn or light-turn 30BR reamer that would work with this setup? I don't want the necks to get too thin because of the stress of feeding up the ramp. It takes a good push. My un-turned dummy round using Rem 7BR brass with a 150 seated measures .332 on the neck. I don't know what a Lapua case would measure, anyone? I got two prints from PTG and the 30BR Robinette looks good but the necks would have to be very thin for the .330 neck, and it has no free-bore. The other print called the 30 BR World Record Holder has a 332 neck which is better and .065 freebore, but the throat is specced at .310 which didn't make sense for an accuracy round. The chamber was also about .021" longer. I've not been able to get hold of Mr. Kiff, so I am asking for others experience here.
Greg

 

[AlNyhus]

Greg, there's really no possibility for a decent 'no turn' 30BR. When the neck is expanded, a 'lump' is formed at the bottom of the neck...this is what used to be the shoulder of the case. You have to turn the 'lump' off, even if you don't turn the o.d. of the neck above it. You can see this 'lump' in the case on the left:

The o.d. of the lump runs around .335-.336. Having a reamer made with a .337-.338 neck (so you don't have to turn the lump off) will give you 'way more neck clearance than you'd want, even in a hunting rig.

You could f-form the 6BR case in the 30BR chamber to get rid of the lump externally, but it's just moved to the inside.

I'd opt a .332 neck chamber with .030 freebore and a .3085 freebore diameter. You'll still need to turn the lump and skim cut the neck, but you can end up with a .010 thick neck and .004 clearance. A .010 thick neck is pretty durable and shouldn't pose any issues for feeding. Not sure if you'll get any dings on the necks when ejecting, but the little Mauser actions don't load the case against the side of the action like the 700 style ejectors do...should be okay.

Just my 2 cents. -Al

 

[gzig5]

Dave and Al,
Thanks to both of you. Some really excellent information there and I really appreciate it. The neck turning itself doesn't bother me, it is the thought of having paper thin necks that need to feed out the magazine and getting mangled that scare me. I'm in the middle of lathe turning ( ala Jackie Schmidt) the necks on 300 pieces of brass that have thicker than expected necks on a 6mm wildcat I shoot in high-power, the 6mm PDK so other than the work, turning is easy. I don't require them to fully clean up as long as they are mostly there. As further explanation for where I'm coming from, I picked up a mini-Mauser and thought it would be neat to build my nine year old daughters first deer rifle on it in 30 BR. 6 or 7 BR would be easier but I have an extra Kreiger 13 twist .308 barrel for my Palma rifle that should do nicely when cut down and I like the idea of a bigger bullet. I am looking for 30-30+ ballistics and am hoping I will be able to leverage the technology of the Barnes and other solid bullets in lighter weights, but they will be the same length as the 150's. I really need to get some of those bullets and measure and make up some dummies, but I wanted to make sure this ground had not been walked before.

As to the "World Record Holder" print, a couple things don't make sense and maybe I got an old print or Jackie could clarify. The throat is .310, the case length to front of the neck is 1.539, the throat length is .064, the lead angle is 1/2 degree. Most of those don't seem like BR spec dimensions to me, but then again somebody set some world record with it.
Greg

 

[AlNyhus]

Greg, that will make up into a slick little hunting rig. The Barnes 110 gr. TSX, Nosler 125 BTip or the Sierra 125 gr. Pro Hunter all work well in that type of application. I know the Sierra is an old school bullet, but they really do the job.

The reason Jackie's reamer has a longer neck is because he f-forms the cases (with a 6mm bullet) in a 6BR chamber with the neck area enlarged. Done that way, the necks don't shorten like they do when they're expanded over a mandrel and the necks are straight with the long axis of the case. The 'lump' is there..it's just inside the neck at the very bottom. Two schools of thought on this:

-If it's below the base of the bullet, it doesn't matter
-The inside of the necks need to be worked on to make them perfect.

I'm of the second opinion and spend more time on the inside of the necks than I do on the outside. For a hunting application where you'll likely be trying a number of bullets of varying lengths, I'd make sure there were no issues inside the neck that would give me any trouble.

Sounds like a fun project. -Al

 

[gzig5]

Greg, that will make up into a slick little hunting rig. The Barnes 110 gr. TSX, Nosler 125 BTip or the Sierra 125 gr. Pro Hunter all work well in that type of application. I know the Sierra is an old school bullet, but they really do the job.

Al, You must be reading my mind. Those are just the bullets I was thinking of. I've watched two deer go down when hit with the 125 Sierra and boy do they drop, but I worry about penetration on a shoulder hit so my go with one of the "super" bullets they've developed for the armor clad deer we have these days.

Thanks for clearing up the reamer thing. I'll get hold of Mr. Kiff one of these days. I've been offered the use of a reamer and gauges by another reamer maker for free because it is for a kid, but I need to find out what he can supply, dimension-wise. Another option would be to go with a no lead like the Robinette and move the throat out as a second operation.

Do you know what the nominal neck thickness of Lapua brass is when necked to 30, dis-regardning the bump at the shoulder? I've got a lot of Rem 7BR brass but want to consider the Lapua as well. I think I read the base of the Lapua tends to be a better fit.

Dave,
I've attached the two prints I received from PTG and there is just some things about the one that don't make sense, especially the throat diameter.

 

[AlNyhus]

Greg, the Remington 7BR cases work nicely in a 30BR 'Robinett' chamber. Matter of fact, Randy used the Rem. 7BR cases in his original 30BR...one of the guns that set the standard for 30BR performance and possibilities.

The .471 back end of the chamber works great with existing dies...and the Rem. 7BR cases are just enough smaller at the back so you get good sizing of the area ahead of the extractor groove w/o any tightness that can sometimes occur if the reamer runs to the high side of tolerances.

All my 30BR barrels have the throats done as a seperate operation. Stan Ware had Dave do the reamer with no throat and we've been well satisfied. Besides giving a lot of flexibility, a throat done seperately does offer some advantages when it come to getting the bullet started down the bore in as straight a manner as possible.

Good shootin'. -Al

 

[1shot]

I would like to apologize in advance to anyone that feels I’m high-jacking this thread, but I’m in the early stages of building a 30BR suppressed bolt rifle on a Rem. 700 action. It makes sense to me to stuff a 190-220gr. SMK and screw a 1-8 twist bbl. on a standard bolt face receiver and go play. I looked real hard at the .223-based cartridges, but I think the 30 BR is the way to go for this application for both simplicity and accuracy. So far the only variable is the freebore, but that won’t take much to figure out once I get some 30BR brass to get the dimensions from. Any comments, questions advice or concerns are truly welcomed.
Thanks,
Lloyd

 

[gzig5]

Greg, the Remington 7BR cases work nicely in a 30BR 'Robinett' chamber. Matter of fact, Randy used the Rem. 7BR cases in his original 30BR...one of the guns that set the standard for 30BR performance and possibilities.

The .471 back end of the chamber works great with existing dies...and the Rem. 7BR cases are just enough smaller at the back so you get good sizing of the area ahead of the extractor groove w/o any tightness that can sometimes occur if the reamer runs to the high side of tolerances.

All my 30BR barrels have the throats done as a seperate operation. Stan Ware had Dave do the reamer with no throat and we've been well satisfied. Besides giving a lot of flexibility, a throat done seperately does offer some advantages when it come to getting the bullet started down the bore in as straight a manner as possible.

Good shootin'. -Al

Dave and Al,

You guys are great. Thanks so much for the excellent information.
A Robinette'ish reamer and seperate throating may be the way to go. I think I now have the tools I need to decide.

Dave, You may be onto something with that cast bullet theory. I'll follow up if I find out.

Greg

 

[gzig5]

I would like to apologize in advance to anyone that feels I’m high-jacking this thread, but I’m in the early stages of building a 30BR suppressed bolt rifle on a Rem. 700 action. It makes sense to me to stuff a 190-220gr. SMK and screw a 1-8 twist bbl. on a standard bolt face receiver and go play. I looked real hard at the .223-based cartridges, but I think the 30 BR is the way to go for this application for both simplicity and accuracy. So far the only variable is the freebore, but that won’t take much to figure out once I get some 30BR brass to get the dimensions from. Any comments, questions advice or concerns are truly welcomed.
Thanks,
Lloyd

Lloyd,
No hard feelings but this is the second thread of mine on the 30BR that you've piggybacked onto, and I don't think you are getting what you are looking for. I encourage you to start a separate thread with your question so you can get your answers and not confuse the issue. What you are looking for and what I am are separate things.

Regards,
Greg

 

[1shot]

Greg,
Out of respect to you, a PM was sent.
Lloyd

 

[1shot]

Thats because your in box is full.
Lloyd

 

[Larryh128]

If deer are the main objective, as good a job as 125 Sierra do, definitely try 130 gr Barnes TSX. Literal hammer.

 

[gzig5]

If deer are the main objective, as good a job as 125 Sierra do, definitely try 130 gr Barnes TSX. Literal hammer.

That was my intention. My guess is that bullet is close to the length of a 150 spitzer and will be about as long a full copper bullet I can fit. I like the 125 Sierra and have seen two deer drop in place from it, but don't think it is a good bullet for an inexperienced hunter. I want something that will expand but still hold together, all while fitting in a 2.350 mag box. I'd also like to try the 110 TSX

You wouldn't happen to have a bullet I could purchase or trade for would you? PM me if you can. I'd like to get one for determining throat length on the reamer and everyone is out around here and I won't be putting in a mail order for a while.
Greg