Information Request for 30-06 load development

[charliewhisky]

I am somewhat new to the development of an optimum long range round although I feel that I understand the basic concepts and physics of the process.

My problem is a lack of experience and I am hoping to tap into some here.

I am reloading for a Remington Model 700 Long Range in 30-06. It has the stock 26" heavy barrel.

I am working up a 200gr ELD-X bullet using RL-17. I picked the 200 grain because I had a lot of time to compare ballistics and I wanted to take down deer and hogs at both the more common, less than 100 yard, ranges and at longer ranges. I will admit to also wanting to impress at the range at 500+.

This discussion is about load development for the round.

Hornady identifies the following charges and projected FPS for RL-17:
53.1 / 2600fps,
54.3 / 2650fps.

I ran a series of .1 increment charges beginning at 52.5 gr (2702fps) and ending at 54.1 (2776).

There appeared to be two points on the graph that indicated probable "flats" that would allow for minor charge fluctuations without disturbing the spread. one was at about 52.8 and the flatter at 53.9gr and 2706fps. I used the 53.9 grains. I was using a new chronograph that I intend to verify against another unit.

Examination of the fired casings, to my inexperienced eye showed a very slight over pressure at 53.9 grains. I asked a very experienced shooter for his opinion and he suggested that it was well within acceptable pressure. he also suggested that at 2706fps I was shooting a lighter load than I could shoot.

Here are the questions:

1) Can the 26 inch, 1 in 10, barrel produce the observed increase in FPS over the Hornady 23.75 inch test barrel? (expected was less than 2650fps and observed was 2706fps average. At 54.3, Hornady's suggested max grains, I clocked 2800FPS.)

2) Is it surprising that the .4 grains less than the suggested maximum RL-17 produces an average velocity that exceeds the 2650fps maximum suggested charge velocity?

3) I know that Hornady numbers are conservative. Does anyone have any experience with 200 grain loads exceeding Hornady 2650fps top end?

4) At what FPS would you expect optimum long range performance for a 200 grain bullet in a 26 inch barrel?

5) should I back off and look for a sweet spot at a lower fps?

4) is my chronograph screwed?


Thanks in advance.

 

[BallisticsGuy]

Okie dokie.

I'll bet a crispy dollar bill that'll work in any machine that you're pressures are near or at max. 2700fps with a 200gn bullet is really gittin it but if you think about it, 2650 is not so wild and barrel length explains the delta.

Pressure signs are notoriously hard to "read" until things are already way too hot. I wouldn't take things any further on the charge weight.

.1gr increments is a pointless WOMBAT (waste of money brains and time). Coarser increments will save you the WOMBAT expenditure. .5gr is a totally acceptable increment. If you feel the need follow up on interesting loads with .2gr increments to validate your velocity stability assessment.

1. Yes. 2" of barrel past 24" might get you 50fps. 2650 + 50 = 2700
2. Not at all. Different barrel/primer/powder/case/bullet's can skew results. The skew you've observed is well within the explainable given the totality of your combo.
3. Yes. Don't.
4. You have left at least 3 significant terms in your question undefined and so it is impossble to answer. Your load's doing just fine to get you well over 1000yrds.
5. Meh. It's not like you're running so hot that somethings going to break but be careful about leaving the ammo in the sun and maybe think about cutting back .3 grain to give yourself a little head room. It'll be easier on brass so the brass will last longer.
6. If it's an optical type (sits out in front of the gun on a tripod) then the error that's innate in the device is enough to make very tightly refined numbers oxymoronic.

FWIW, OP, you worry too bloody much. Relax a little.

 

[Axl]

You left out 1 bit of info, what were your groups like?

 

[charliewhisky]

Okie dokie.

I'll bet a crispy dollar bill that'll work in any machine that you're pressures are near or at max. 2700fps with a 200gn bullet is really gittin it but if you think about it, 2650 is not so wild and barrel length explains the delta.

Pressure signs are notoriously hard to "read" until things are already way too hot. I wouldn't take things any further on the charge weight.

.1gr increments is a pointless WOMBAT (waste of money brains and time). Coarser increments will save you the WOMBAT expenditure. .5gr is a totally acceptable increment. If you feel the need follow up on interesting loads with .2gr increments to validate your velocity stability assessment.

1. Yes. 2" of barrel past 24" might get you 50fps. 2650 + 50 = 2700
2. Not at all. Different barrel/primer/powder/case/bullet's can skew results. The skew you've observed is well within the explainable given the totality of your combo.
3. Yes. Don't.
4. You have left at least 3 significant terms in your question undefined and so it is impossble to answer. Your load's doing just fine to get you well over 1000yrds.
5. Meh. It's not like you're running so hot that somethings going to break but be careful about leaving the ammo in the sun and maybe think about cutting back .3 grain to give yourself a little head room. It'll be easier on brass so the brass will last longer.
6. If it's an optical type (sits out in front of the gun on a tripod) then the error that's innate in the device is enough to make very tightly refined numbers oxymoronic.

FWIW, OP, you worry too bloody much. Relax a little.

Thanks for the great response. I'm old enough to know the only dumb question is the one you don't ask and I appreciate the thoroughness of the reply.
With regard to question 4, It was kind of a dumb question. I chose the 2707fps because of the ballistics. A 2.5 inch rise and three inch drop with a 207 yd Zero and the ability to maybe shoot out to 600 using mil dot holdovers. My question should have been. Is more speed OK? You gave me that answer.
With regard to #5, I will definitely back off and look for a node that gives me minimum vertical spread. I intend to shoot enough that the brass life is important too. That's what retirement is for.

 

[charliewhisky]

You left out 1 bit of info, what were your groups like?

Hi, my best six round group at 101 yards from the bench, on a sandbag, was 1/2 inch vertical spread and 7/8 horz spread. Shooting steel out to about 300 was no problem. At 500 the rifle can shoot better than I can. I have been out of the country for four months and am anxious to get back to the range.