154 LBT .30 call bullets????

[Larry Gibson]

About 3 years ago some of us were involved in a discusion of accuracy at high RPM. Someone sent me some 154 LBT bullets to try in the .308 and 30-06. I did manage some pretty decent accuracy with them at 2315 fps (138,900 RPM) in my M70 Target with a 1-12" twist. Then I went to Iraq and the testing fell by the wayside.

Who sent me the bullets? Sorry but I can't remember and failed to write it down.

Anyways I recently came into a very nice 27.5" Palma barrel chambered for .308 and threaded for a M98. The previous owner had fired less than 2 boxes of Sierra Palma bullets through it and moved on to a 6.5 something or other. My buddy who did the barrel work for him had it on his shelf in his gunshop. I asked what he wanted for it and he said since no one wanted a heavy barrel with a 1-14" twist in his neck of the woods that if I showed him how well it really shot with cast bullets he'd give it to me. You think I said no!!!!

About 40 years ago another friend (see, I have more than one) started making his own kevlar/fiberglass stocks. He made a mould using a Savage 112V stock. His first stock didn't turn out to good but his 3rd one turned out pretty nice. I went over to see it and helped him bed an action in it. His second stock was in the garbage can. Had a few imperfections but all are cosmetic. I joked with him and said my bill for the bedding would be the 2nd stock. He gave it to me and bought the beer anyway. I had a M98 action that had been D&T'd already so I bedded it into the stock and made a "test" rifle out of it as it is quite easy to change barrels on a M98. Yesterday I popped the barrel that was on the M98 off. Measuring the shank of the Palma barrel showed it to be a good fit to the reciever. I screwed it in and it tightened up and it screwed in right at 1/3 thread farther than on it's previous action. The bolt was just short of closing on a GO guage. Once fired 7.62 cases FL resized with a +.004" shell holder were a slight crush fit. Factory .308 and US Military 7.62 chambered fine. I could "bump" the chamber with my own match reamer but I think I'll leave it tight. Below is a picture of the rifle. I have and old but good Weaver T16 on it.

Guess I've got a lot of casting and testing to do. I've loaded up the remaining 154 LBT bullets to see how fast they can be pushed with good accuracy in the 1-14" twist. I also loaded some RCBS 30-150s. Any suggestions or ideas?

Larry Gibson

[26Charlie]

Harry Pope ( the barrel maker) was a proponent of the 14" and 15" twist for .30 cal target rifles in the 1930's. The 10" twist was a relic of the .30-40 Krag caried over to the .30-'06; the .308 had a 12" twist. I have had no problems with cast long bullets (311284 and 311299) around 210-220 gr. in either the .308 or in the .300 H&H, which also has a 12" twist. Based on this, I wouldn't hesitate to try cast bullets up to 180 - 190 gr. in the 14" twist barrel.

[Larry Gibson]

Harry Pope ( the barrel maker) was a proponent of the 14" and 15" twist for .30 cal target rifles in the 1930's. The 10" twist was a relic of the .30-40 Krag caried over to the .30-'06; the .308 had a 12" twist. I have had no problems with cast long bullets (311284 and 311299) around 210-220 gr. in either the .308 or in the .300 H&H, which also has a 12" twist. Based on this, I wouldn't hesitate to try cast bullets up to 180 - 190 gr. in the 14" twist barrel.

Ok, 311299 is on the list. I also have had good success with it in 1-12 twists in my M94 30-30 (single shot as the bullet is to long for feeding from the mag without excessive deep seating. Will be interesting to see what the 1-14" twist will do with it. Thanks for the input.

Larry Gibson

[Bass Ackward]

If those LBTs were spitzers, I sent them to you. But that was probably 4 years ago now.

[Larry Gibson]

If those LBTs were spitzers, I sent them to you. But that was probably 4 years ago now.

Spitzers they are, 4 years? Time flies when we have fun. Well I've got them loaded up with 47.5 gr RL19 which shot right at MOA in the 1-12" twist M70. Also with 30 - 44 gr of a very slow lot of milsurp 4895.

I've no "benchmark" with this new 1-14" twist barrel as I've not shot it. What are your thoughts on shooting a couple of known accurate loads with Speer 130 HP and 150 gr MK bullets to sort of establish a benchmark? Or should I just go with cast and see how she does?

Larry Gibson

[Bass Ackward]

Spitzers they are, 4 years? Time flies when we have fun. Well I've got them loaded up with 47.5 gr RL19 which shot right at MOA in the 1-12" twist M70. Also with 30 - 44 gr of a very slow lot of milsurp 4895.

I've no "benchmark" with this new 1-14" twist barrel as I've not shot it. What are your thoughts on shooting a couple of known accurate loads with Speer 130 HP and 150 gr MK bullets to sort of establish a benchmark? Or should I just go with cast and see how she does?

Larry Gibson


Larry,

Well there is the practical side here and that is to establish the benchmark. I like that because it should begin the breakin process.

But I am a realist too and realize that you probably already shot them before you read this reply. :grin:

[Larry Gibson]

Larry,

Well there is the practical side here and that is to establish the benchmark. I like that because it should begin the breakin process.

But I am a realist too and realize that you probably already shot them before you read this reply. :grin:

Actually I haven't, not to say the thought didn't cross my mind. I did go to the range yesterday and shoot the 30-150-FNs and your 154 LBTs. It was a cold blustery day with wind, hail and rain. But there was just enough sunshine too to give me hope! With the 30-150-FN 5 shot groups hovered between .9" and 1.8" (had a called flyer - 4 shots were right at 1") between 1521 fps and 2230 fps. Between 2378 fps and 2631 fps groups were between 2.15" and 2.4". Those bullets are holding accuracy in this 1-14" twist barrel upwards of 25-30,000 higher RPM than in a 1-10" twist.

With your 154 LBT bullets the RL 15 load did not fare well in this barrel. With a full case of 48 gr the 10 shot groups was right at 2" running 2446 fps. With milsurp 4895 accuraccy ran from 1.1" to 1.5" up through 2505 fps. With 42 gr the velocity was 2759 fps and it grouped 2.8"! With 44 gr I got some bolt lift stiffness but it still grouped 4.6" t 2855 fps!!! I got no leading with either bullet and only cleaned the barrel between bullet loads - 50 shots without cleaning and no leading at those velocities. Your bullet had the blue lube and I used Javelina on the 30-150-FN.

Looks like there's some real potential here with this palma barrel. I'll cast up some more of the 30-150-FN (unless you want to sell that LBT mould?) and can't wait for the 311-150-GC GB to come in and test it. A 2200+ fps cast bullet load with it that shoots MOA would be a very fun ground squirrel shooter, maybe rockchucks too!

Larry Gibson

[Bass Ackward]

Looks like there's some real potential here with this palma barrel. I'll cast up some more of the 30-150-FN (unless you want to sell that LBT mould?) and can't wait for the 311-150-GC GB to come in and test it. Larry Gibson


Larry,

LBT is still in business, you can get one made. Veral told me that he remembered making this particular mold for a guy that wanted it for low velocity use and is why it has the narrow GC groove. So getting one of his designs with a wider groove will get more pressure away from the base and allow higher velocities. It will also raise bullet weight. That was supposed to be a 160 grain. Veral claimed that is why that particular design is finicky above 2000 fps. He was shocked I got anything at 2600 fps.

I use the 06 at 2600 every year and as long as it is over 85 degrees, I am sub MOA. So hell no, I don't want to sell that mold!

When the accuracy contest was big, I got real close to Dan's requirement for 1" groups at 200,000 RPMs. I had 3 groups from 1 3/8" to 1 3/4" at 2900 fps in a 10 twist. That is close enough to call it 200,000 RPM, just never, not once got MOA. I was using a hollow pointed 311440 and RL15 to do this. That is why I got in on the 311440 solid group buy because that single cavity was rocking my world. And the limitation was the balance of the bullet from trying to mold .... PERFECT hollowpoint bullets. That and a too wide nose. A small hollow point spitzer of that same weight would get me sub MOA, I'll bet.

But alas, the Lee 311440 version was heavier and carried less lube when sized down and just not as accurate without the hollow point. Same load area was at best, 6". So this shows just how sensitive and critical bullet weight and pressure on the base is between great, OK, and poor results. Lube is another biggie. So is primer. So is .... everything. Get the picture?

:grin: But they don't fly apart!

[Larry Gibson]

So hell no, I don't want to sell that mold!



A rather selfish attitude! Just kidding, does the mould have a number that I can reference to LBT?

In looking at that bullet design there is no nose as such. The body is full caliber to the ogive which gives it maximum support in the case neck and throat of the rifle. I think that reduces a defects from obturation during acceleration. I maintained very good accuracy up through 175,000+ RPM (2505 fps) and still had very reasonable accuracy up through 193,000 RPM (2759 fps). I got sticky bolt lift at 199,735 RPM (2855 fps) but accuracy fell off to 4.6". There was no indication that bullet was coming apart as the holes in the target were very nice and round at .30 caliber. Even at 2.8 MOA that bullet at 2759 fps would be a deer killing machine out to 300 yards.

Larry Gibson

[wiljen]

I'd love to see a pic of the bullet you are discussing, it sounds like it might make a real good candidate for a group buy mold.

[Bass Ackward]

A rather selfish attitude! Just kidding, does the mould have a number that I can reference to LBT? Larry Gibson


Larry,

.310 160 SP

It's still listed as an option on his site. If you cut a short enough throat when you did that up, Veral shows as low as a 140 grain spitzer in 30 caliber. Could get 3000 fps outta that one. :grin:

Bear in mind that those bullets I sent you were my ACWW mix at 14 BHN and some of the tin was .... burnt outta those too. So in truth, they may have only beed 13. Who knows. A little harder might have worked better in your .... new barrel. Don't worry, it will smooth out and get better. :grin:

HTH,s

[Bass Ackward]

I'd love to see a pic of the bullet you are discussing, it sounds like it might make a real good candidate for a group buy mold.


Wil,

http://www.graybeardoutdoors.com/lbt/molds.htm


Scroll down to it.

[Bass Ackward]

Savage is coming out with a Benchrest action. Supposed to be single shot and heavier like it was sleeved, either left or right hand. Only the actions for right now.

I found a relatively new barrel company doing cut rifling with accuracy down to the fourth decimal point.

Might be a no throat 06 with about .006 tall lands on the drawing board shortly. I w....a....n....t MOA at 3000 fps!

Darn you anyway. :grin:

[Larry Gibson]

Savage is coming out with a Benchrest action. Supposed to be single shot and heavier like it was sleeved, either left or right hand. Only the actions for right now.

I found a relatively new barrel company doing cut rifling with accuracy down to the fourth decimal point.

Might be a no throat 06 with about .006 tall lands on the drawing board shortly. I w....a....n....t MOA at 3000 fps!

Darn you anyway. :grin:

Funny how great minds think alike...I was just thinking the same thing! Actually a simple wildcat i call the 30x57 should do it. Its simply an '06 die shorted enough so an 8x57 case ends up with a .30 cal wit the '06 length neck. Easy to short chamber the barrel with the '06 reamer. Great cartridge that feeds reliably and gives better ballistics in M91, M95 and short actioned M98s. Of course with the increased case capacity .308 ballistics are achieved at lower pressure. However in the application we're discussing the '06 case capacity might be desirable for using the slower burning powders.

Here's the 30x57 between the .308 and the '06.

Larry Gibson

[Larry Gibson]

I'd love to see a pic of the bullet you are discussing, it sounds like it might make a real good candidate for a group buy mold.

Here is Bass's 154 LBT to the right of the 30-150-FN RCBS for comparison. Note there is no bore riding nose. When seated so the top lube groove is just covered by the case mouth the lands on my Palma barrel just touch the bullet ogive. The top of the GC is at thebottom of the case neck. What Bass is talking about is in an '06 with no throat the whole bearing length of the bullet from the base of the GC to the beginning of the ogive just fits in the case neck. Other than posible "sqatting" of the bullet back into the lube grooves there is nothing to get unconcentric during acceleration. A very well designed bullet for high velocity in the '06 length neck or with a tight throat.

Definately a good candidate for a GB mould!!!

Larry Gibson