Bit dissapointed in some 30-06 velocities

24" 30-06 with very worn throat (would take a 200g bullet way past SAAMI col to reach lands)and fairly pitted but accurate.

62gr RL22, WLR, 165gr Nosler BT @3.340" ie 1gr under Nosler book max. The book max shows 3,000fps I get 2720fps

Same as above but using MRP - identical velocity

150gr Hornady interbond and 53grVVN150 2,730fps, Hornady show 2,900fps with 53.6gr

Yeah I know velocity isn't all etc etc but I allready have a very accurate 7x57 that is at this sort of velocity and I really want at least 2,800fps from 165s and around 3,000fps from 150s.

Does barrel wear reduce velocity appreciably and if so does pressure reduce to the extent that one can work up past max to get the sorts of velocities talked of in most books (I note my old speer book is much more conservative with velocities than Nosler and Hornady...)

Temp was about 1celcius and chrono is pretty reliable. No pressure signs that I could see.

What to do - work up further or go for more middle of the road double base such as RL19, H414?

I would say you are victim of wear and tear. But I only think your velocity is about 100 fps slower than what it would normally be as those book ratings are too high.

I'n no where near qualified to tell you it might be ok to go with more powder. If it was my face sitting behind the bolt I would strongly conside the advice that will be following! Just because you have a slow exit speed might not mean you didn't make pretty good pressure at "ignition". Sounds like you might have an older firearm and who knows what it's been through in it's life...could be stressed parts from a past owners pratices etc.
100fps isn't a killer especially if the gun is accurate. Go with a bullet like the tsx that retains it's weight and you can go with lighter bullets a little faster and get the same results as the next higher class bullet. Ie...the 168tsx will usually have 90% wt retention and has a ton of Sectional density....easily as good a bullet as you normal "lead/copper jacketed" hunting bullet.
Just mho!

Yes, the throat is to blame.

I experimented with an oversize throat in the '06 and saw velocities drop 50+ fps after rethroating. Pressures were lower, too, as measured by a strain gage. After adjusting the powder charge to restore normal pressures, the velocities almost, but not quite, returned to where they had been before the rethroating.

I could suggest that you use your chronograph as a guide to increase the powder charge until velocities were near normal, but then Hot Core would point out examples of how sometimes velocity is not a reliable indication of pressure, and he would be half right.

My experience with 30-06 is much like yours in terms of velocity. I have three of them that will do what you want and a bit more when pushed, and one that won't. The one that wouldn't was an old model 30 Remington complete with sewer pipe bore. The good news was that I could make it shoot respectably with heavy round nosed bullets, the bad news -I traded it.
Talk about stupid, I have no idea why I dumped that gun as it was in good shape other than the bore, and it had remained untapped over the years. Just why I couldn't live with the Lyman peep sights I'll never be able to explain, but I guess it could best be summed up this way: I didn't appreciate it for what it was -a short range thumper.

I've decided to resurrect some VVN550 150gr loads that I killed due to bad daytime muzzle flash despite good 2,900fps+ velocity and accuracy. Have also loaded some slightly heavier charges of RL22 for the 165gr.

I am wary of book max or plus book max but with chrono, Quickload and a wary eye I shall proceed gently. 62gr RL22 showed no pressure signs in 85fahrenheit and a barrel too hot to leave ones hand on so I don't think I'm exactly redlining it.

Ordinarily I would be happy with accuracy and 2,700fps but this rifle is specificaly required for beanfield style hunting ie 200-400yards (allthough the 300-400yards will only come with a good bit of practice!)

quote:

Originally posted by 1894mk2:
Bit dissapointed in some 30-06 velocities

62gr RL22, WLR, 165gr Nosler BT @3.340" ie 1gr under Nosler book max. The book max shows 3,000fps I get 2720fps

Same as above but using MRP - identical velocity

This is hardly a suprise because IIRC RL22 and MRP are the same propellant with different labels.

Kinda like H414 and W760 are essentially the same...

THE limiting factor loading RL22 into a 30-06 with a 165gr bullet isn't pressure, but how much RL22 you can make fit inside the 30-06 case.

Nosler shows RL22 at 63.0gr at 105% of case capacity.

I can say that making it fit is somewhat easier with neck sided brass....


AllanD

RL 22 is on the slow side for an '06 with bullets lighter than 180's. If the RL's are readily available, try RL-19 (or Norma 204) with your 150-165 grain bullets and I think you'll be pleased.

And yes, if a throat is worn it requires more powder to reach the same velocities and PRESSURES as with a tight throat. The worn throat acts like a freebored chamber and in effect increases the volume of the pressure vessel.

Incidentally, I have a rifle with a throat worn so much that it need 2 grains of the same powder to reach the same velocity as when new. It still shoots with the same excellent accuracy, however, so "alligator skin" in the first few inches of bore doesn't necessarily mean that a barrel needs retirement.

quote:

Originally posted by popenmann:
...I could suggest that you use your chronograph as a guide to increase the powder charge until velocities were near normal, but then Hot Core would point out examples of how sometimes velocity is not a reliable indication of pressure, and he would be half right.

Hey Popenman, Thank you. I've always considered being "half right" is better than "dead" wrong!

Our old buddy Karl has a right nice bit of info concerning Chronographs and Pressure that you all might (half way) enjoy.