Home Forums Reloading Big Game Rifles 7mm-08 18" vs 22" Ruger American

I was curious to see what the difference in velocity would be between an 18" and 22" barrel in the 7mm-08. I took a standard 22" Ruger American and 18" Ruger American compact and put various loads through them with 139 and 120 gr bullets using several different powders and this is what I got. Some loads are reduced and others are closer to max. All loads used Hornady brass and winchester large rifle primers.

loads:
139 gr interlock 18"=2,685 22"=2,797 Difference=112
46 gr Alliant 2000MR

139 gr interlock 18"=2,513 22"=2,646 Difference =133
47 gr H414

139 gr interlock 18"=2,341 22"=2,447 Difference=106
37 gr 8208XBR

120 gr ballistic tip 18"=2,899 22"=3,027 Difference=128
49 gr 2000MR

120 gr ballistic tip 18"=2,737 22"=2,873 Difference=125
49 gr H414

Avg Difference = 120.8

So it looks like the 18" lost about 121 fps to the 22". Avg loss was about 30 fps / inch.

That is good to know. I thought it would be closer to 50 FPS per inch.

Yeah, that is really impressive actually. I have the 7mm-08 in the standard, and the .243 in the compact. Both are currently wearing standard length stocks, though. I was just kinda guessing close to 200 fps. But, I guess in the short cartridges with a good primer and the relatively fast powders, it's burning pretty efficient, even at 18".

Great to know. Appreciate the effort!

The rule of thumb I've always heard was 25 fps/inch.



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One thing I forgot to mention was the difference in noise and muzzle blast. With the reduced loads the difference was noticeable but with full loads the difference was pretty substantial. That short barrel is rough on the ears even with protection.

I don't know why you'd go 18" with a 7-08. Seems like you're cutting the legs off at the knees. My last 7-08 had 22" on it, and that was about right. I have a new 24 inch barrel to put on my Savage 110. I'm anxious to see how that goes.

Cool report, though, it's good to see this information.

The 18" belongs to a women who's 4'10". The length and weight fit her well. She took her first buck this season with that gun and a mild load. 139 interlock @ 2400fps. The shot was about 40 yards or so. The deer was quartering to a bit and the shot landed a bit back for that angle but the near lung and liver got distorted and the deer dropped inside 50 yards.

Good info, thanks for posting.

Thirty feet per second per inch even agrees with my .375 H&H, which is a lot bigger than the 7mm-08. When I cut the Whitworth barrel from 24 to 22", I lost 65 fps with my favorite 300 gr load.....or 32.5 fps per inch.

Interesting, I ran a similar test this past summer but my interest was geared toward slow vs. fast burning powders in short vs longer barrels.
I too selected the 7-08, rifles were Ruger American compact 18", Rem.700 youth 20" and custom Mauser 24" wanted to throw in 22" but was unable to beg or borrow one. As far as the rifles go I know I was comparing apples to oranges
but felt it would be similar to when someone throws out the question of what powder would work best in a short barrel and they get a multitude of answers from folks using many different rifles and barrels. I shot bullets from 120 through 160 grain, and powders from IMR 4895 through H4831 for burn rates. Bottom line The 18" lost an average of 30 fps vs the 20" and slightly less per inch vs the 24 inch at 26 fps. The slower powders added nothing to the lighter 120 and 140 class bullets, but were helpful with the 145 and up bullets. I never went over the book max loads
so no tweeking or fussing to try and eek out a little more fps. All loads were assembled on Hornady brass and Win LR primers. Finally I see why gun scribes are reluctant to do this type of comparisons. Very time consuming what I thought would take about a week stretched into almost 3 months what with normal life, weather, etc getting in the way.

The 375 H&H has a moderate case capacity to bore ratio.

...................In doing the math, the average % velocity loss of all five of your loads was 4.47%. Using identical loads with different powders and bullets, ""just might"" yield for you an even lower average of less than 4.47% across the board.........Here is why.......A link to an article that you might find very interesting that also uses a Ruger 7/08. Scroll down and read on from the heading "Short Barrel, Long Reach"......

www.shootingtimes.com/long-guns/longgun_reviews_scout_102606/

In this article, the difference in barrel length is 7.5" (16.5" vs a 24" barrel) rather than the 4" difference you experimented with. And yet, the author's test result was a 4.5% difference with a 7.5" difference in barrel length. Have a good feeling that you may get that % down to about 3 to 3.5% using other bullets and powders.

My own chrony results were right on par with the above link, as I wanted to compare my results with that 2005 (approx) article which was the purpose of my experiment which took place several years ago and took many weeks to do as time permitted.

Using identical handloads, my 300 WSM Ruger Frontier with its 16.5" barrel, retained on average, 95.43% the speed of two 24" barreled 300 WSMs (about a 19 fps loss per inch on average) using the typically normal 300 WSM powders such as RL17, H4350, H4831, IMR4350, N165, W760 and Magpro to name a few that we had on hand. The bullets primarily used were the 155, 168, and 190 gr Berger hunting VLDs. Primers were WLRM with Winchester fully sized brass.

Try some different powders and bullets using the same two Ruger American 7/08 rifles and see what you come up with the next time.

You just may close the gap down by a % point to 1.5% - 1.75%......

I sawed my 250 Sav AI barrel from 25 to 21 inches. With several handloads the average velocity loss was 95 fps.

Given the medium contour barrel, the improvement in balance was well worth the compromise.

Does the RAR 18" shoot better? Thinking it might.

Not sure why it would necessarily. The barrel contour is heavy enough that even the 22" one should be pretty stiff.

I haven't shot my 22" 7mm-08 stainless yet, but I will say the 18" .243 was printing touching shots at 100 yards the first day on the range, without too much effort. I don't expect any less from the 7mm-08.

I've been shooting the18" for several months now and have found it to be super consistent with its accuracy. It will shoot just about any load well. The 22" is new, I've only had it a few weeks and it has limited use so far. It's a bit more finicky about loads than the 18". While the 18" will keep just about anything inside an inch the 22" is opening some loads to 2". That being said though it does look like the stock on the 22" could be contacting the barrel. I'll have to sand the barrel channel out and give it another try.

I sanded down the stock today on the 22" and did more shooting. It didn't change anything. The 22" will shoot sub MOA with some loads and closer to 2.5 MOA with others. Oh well, not a big deal that's what most of my rifles tend to do. The compact is just a freak. I really haven't found anything it doesn't like yet.

[quote=obie458]One thing I forgot to mention was the difference in noise and muzzle blast. With the reduced loads the difference was noticeable but with full loads the difference was pretty substantial. That short barrel is rough on the ears even with protection. [/quote


Ya, ~25% more psi as the bullet exits the muzzle with the shortewr bbl.