Range Report M118LR and 17.5" Bolt Action. Trying to figure something out without chronograph.

[wjwill]

Please forgive the question if it is considered dumb.

I am trying to figure this out without a chronograph as I do not have one. I purchased 500 rds of M118LR from a hide member here a couple of months ago. I spoke with the member I got the ammunition from and he said my bullet speed on dope card looks slow. Below are the specs on the rifle and some screen shots from Strelok Pro. I pulled the data for the M118LR from the online library. Has any one on here ever shot M118LR from a 17.5" barrel that might have some info to share? Is it possible to figure out without a chronograph? This is by far some of the most accurate ammunition that I have shot.

Remington 700 S/A
17.5" Brux barrel (MTU contour) (1:10 twist with 5R rifling)
McRee Chassis
US Optics ST-10 JNGMOA reticle
TPS steel rings
NF 20moa base

 

[jhunter]

I’m at 2650fps with a 20”

 

[DairyDictator]

Honestly you really should just invest in a chronograph. It's an invaluable piece of kit for shooting at range. You don't have to go crazy and buy a magnetospeed or a labradar. Even the caldwell can be had for around a hundred bucks and works just fine.

 

[DairyDictator]

The only other way I know of is to shoot a very tall target out at 300 plus and record exactly how long it drops. Not sure if Strelok does it or not but some programs will calculate MV based on your bullet info and drop data. If it doesn't just play around with the velocity till things match up then verify and play around again.

 

[wjwill]

I made up my mind lastnight. Going to stop being a cheap bastard and spend the cash on a chronograph. Lately, I have been buying all the M118LR I can find and AICS mags. So I was being cheap on everything else.

 

[tnichols]

Establish a solid 100 yard zero. Plug in 2600 +/- into your ballistic calculator and shoot a 500 yard plus target. Measure the impact dispersion above or below the waterline and plug that number into the calculator along with the distance to “true” your muzzle velocity. Adjust elevation, and reshoot to verify. Done. I only shoot over a chrono during initial load development.

 

[wade2big]

If you have at least 500 yards to shoot, a chronograph is not needed. It’s not even desirable to me.

 

[wjwill]

I have about 800 yards

 

[wade2big]

I have about 800 yards

Guess your speed and put it in a calculator. Dial for 500 and shoot. Measure correction with reticle. Adjust your speed in the calculator. Use corrected dope, dial for 800 and shoot a group. Measure correction if any and adjust speed in calculator to match. Many times 500 will get you dead on. Some times you may have to tweak a .1 or so.

 

[wjwill]

I am going to try it in a week or two when I go shoot. This is why I have always loved this board, the knowledge here is second to none when it comes to precision shooting.

 

[JustSendit]

With a 17.5" barrel, my guess is in the 2550ish depending on the lot.

I have plenty of times trued a MV on a 4" I-beam at 400m with 118LR, come in holding 2.7mils, and go from there. It's very effective. If you can push it out at transonic it'll be a little more accurate.

Curious what MV you get with that barrel in a bolt gun. My 16.5 OBR with 118 is under 2500, or just at it depending. AB39 is about 100fps faster, generally.

 

[Sixfivesavage]

Some M118LR from my lot of it out of my AX factory tube that has been cut back to roughly 17.5" runs 2564 avg.

 

[wade2big]

FGMM 175gr is 2750 out of a fast 26” barrel. I have seen 2500-2550 out of 20” barrels depending on the rifle. Unless this ammo in question is extremely hot, I would expect less than 2500fps out of a 17.5” barrel.

Of course @Sixfivesavage says he gets 2565 so i guess that shit would do well over 2800 in a 26”. I guess it is hot.

 

[8up]

I say summertime temps, it will be about 2575'ish area for that 17.5 bolt. Winter temps around low 2400 area.

 

[Sixfivesavage]

FGMM 175gr is 2750 out of a fast 26” barrel. I have seen 2500-2550 out of 20” barrels depending on the rifle. Unless this ammo in question is extremely hot, I would expect less than 2500fps out of a 17.5” barrel.

Of course @Sixfivesavage says he gets 2565 so i guess that shit would do well over 2800 in a 26”. I guess it is hot.

For clarity, my AX barrel is a factory 20" that was cut back. Its right at 18" end to end when not in the gun. I've shot a lot of that ammo before I switched to McCourt loading 185 jugs for me. This pic was taken June 19th of last year...

 

[MisterAnderson]

A few more points of reference to help you:

• R700 AAC 16.5" w/ FGMM 175 is at 2440fps (Shooting suppressed)
• 20" GAP-10, FGMM 175 runs about 20-30fps slower than M118LR (shooting w/ a brake).
• Change in velocity based on my data is about 40 fps / inch for M118LR on the GAP. I haven't run M118LR through the R700.