.308 Bisley revisited

[300 RUM]

Hello all,
I just chambered a barrel with a "308 Bisley" thinking it was a standard 308win/7.62NATO. Ok that being said the chamber work went excellent, and head spaced it with a standard 308 go/no go gauge which I have been told is fine. Also my understanding is that the Bisley will chamber and function properly with any old factory/ hand loaded ammo designed for the 308win/7.62nato? Also that the Bisley is a much better chamber then the standard? So with all that being said, what is the difference between the two? What will I and what will I not be able to do with this chamber?



The brass I intend to use will be: REM, WIN, Nosler and Lapua
The bullets will be: 155gr & 167gr Lapua SCENAR, 168gr Hornday A-max and possibly 208gr Hornady A-Max

Are there any hints that can be given out to hand loading these bullets?


Thanks

Gene

 

[okedoke]

I've taken a little interest in your concern about how safe the chamber of the .308 bisley & the .7.62 NATO is going to be while shooting a wide range of bullets. First of all according to the Palma rule of 95 the OAL of the bisley was to be 2.805 with a 150gr. bullet & the OAL of the palma 7.62 NATO would be 2.780 with a 155 smk. It appears that you don't have a safety problem but rather chamber throating issue. Perhaps you should consider a switch barrel rifle that changes the rate of twist for the heavy bullets & another for the lighter bullets, also you must check the magazine length that could possibly cause you to seat the bullet to deep in the case & jumping the bullet .125 to the jamb. there are a lot of variables. I think bullets from 155--200gr. in the same rifle equates to a pain in the neck, the brass you are going to use should not be a problem, it will fire form to your chamber just make sure it is of good quality & is well trimmed. PS -- i suggest you google ...............308 bisley----------- take care craig

 

[Keith Glasscock]

I don't know anything about the bisley chamber, but I do know a bit about shooting 155's and 208's in the same chamber.

It can be done, but (there is always a but) the 208's will be seated past the neck-shoulder junction and that causes flyers. In my case, the flyers weren't horrible, but they would ruin a string in F-class.

The 155's shoot ok in long chambers *if* you can stand to seat them with .090" of bearing surface in the neck. The Bisley is not "long" in my opinion. Last time I looked the freebore was 60 thou shorter than my reamer, and my reamer isn't long enough for 208's

All in all, I've moved away from trying to run multiple bullet weights in the same chamber. Of the bullets you list, I'd shoot the 155 Scenar over anything else (in that chamber). It is a darn fine bullet and has won its share of trophies at long range.

The others in the 168 range are ballistic bricks. The performance just isn't there for longer ranges. There are some really good bullets (in terms of BC) in that weight range, just those two aren't.

The 208 A-max does quite well, but I haven't seen too many trophies won with it.

Last question:
What is the intended purpose and maximum range? That information would help us help you.

 

[300 RUM]

Busdriver:
The rifle is an AR-10
.298/.308 x 26" barrel

I will be sticking to 155gr -167/168gr and maybe (178gr?)bullets for this rifle.
Max range? I can only hope it shoots to a 1,000

 

[Keith Glasscock]

I have a little time flinging lead out of a 26" barrel at 1000 yards. It was a bolt gun though.

155's would stay above Mach 1 if I ran up near max loads. 168's according to others (I didn't test them) are problematic past 800 due to transonic tumbling. 175 SMK's work, but they arrived subsonic if they weren't launched right at max (2650+)

I would also look at the Berger 185 LRBT's for extreme long range. They will get there above Mach 1. They are not well suited to unknown distance though (drop like a rock). Also, they will not fit in a magazine. The nose section is too long, but single-loading would work even in your Bisley chamber.

 

[jbpmidas]

My gunsmith chambered my Brux 10 twist .308 with a Bisley reamer. I'm having good results out of the 185 Hybrid at 2660. You'll have to run the ballistics to see what it would do at 1000, as I have only shot at 600. I'm having no pressure signs and from my ladder test, I could add up to another full grain of Varget. My barrel is 28", so you'd need to take that into account.

 

[300 RUM]

Yea I've been looking at bullet shapes a lot in the past few week as that will be a critical factor to what I can and can not shoot. My magazine will allow a max seating depth of 2.875". I figure if I can get a reliable feed at 2.845" I'll go with it. I like the 155-167 a lot, oh my barrel is also a 1:10 twist so I f I stick below 178gr I believe I should be just fine wouldn't you think?

jbpmidfas is your barrel a .298/.308 bore?

 

[jbpmidas]

I was thinking it was .300/.308, but I'm not sure. I know it is a "standard" bore, not the tight bore.

 

[Keith Glasscock]

I missed that. Tight bores can be problematic with heavy bullets. Be sure to work up slowly because the pressure will come on sooner than you would expect.

 

[jbpmidas]

I will be watching closely when the temperature rises. I think I'm ok with Varget, but I've only got 1 set of eyes!

 

[Keith Glasscock]

I will be watching closely when the temperature rises. I think I'm ok with Varget, but I've only got 1 set of eyes!

Sorry, I was actually speaking of the 298/308 barrel that 300RUM has. We always must be careful though....

 

[300 RUM]

On my AR-15's I use Ramshot exclusivity for .223, but I'm also not looking for any great results most of the time. How ever on my 24" barreled AR-15 with 77gr lapua's I get excellent groups to about 500 yards and for 100 yards my last strings of 5 shot groups was .668dia to .750dia using RL-15. I will most likely stick to Ramshot TAC and RL-15 powder for now seeing I have a lot of it.
Now being that I want/ hope to have the 1,000 yard capability with this AR-10 I'm not against going to a different powder. I will be loading some this afternoon with RL-15 and if weather and life events in general permits I will hopefully perform barrel break-in tomorrow and get a first glimpse at this rifle's potential.

 

[300 RUM]

Is it common that the neck of the casing get dinged up on ejection on a .308 out of an AR-10? I'm getting cases back with the neck dinged up.

ALSO:
I measured my chamber for C.O.L. today and I get an exact 2.80 (just touching L&G) for both the 155gr and the 168gr bullet, not a problem, I guess the .298 bore is cutting off any extra throat I may of had. I was hoping to be able to seat the bullets not any farther then the length of the neck only, but it looks like I will be .030 short on these bullets.
I ask the question: Leave it at 2.80 COL or ream out the throat another .030 to accommodate what I had originality set out for? I know I answered my own question just wanting to hear what you all have to say about this. To be honest I'm thinking about leaving it as is and just sticking with nothing larger the maybe 178gr bullets for this barrel.

 

[300 RUM]

First round of test ammo went well I thought. One of the guys at the range thought the primers looked a bit falter then "normal"? I don't think so, what do you all think?

The load was 41.5gr Ramshot TAC, this is the bottom end out of the book.

 

[Keith Glasscock]

Yes, ARs ding up the necks. I get a scratch or dent lengthwise of the neck on most.

That primer looks good to me - nice, round corners.

 

[300 RUM]

Finished product

 

[okedoke]

300rum, that's a fine looking rifle, i must say i'm a little jealous but i'll stick to the turn bolts i wish you well with the heavy bullet but you will find the right load & have a blast trying to wear - out that tite barrel-------------take care Craig