Difference in Marlin 1895 & 1895G Ballistics?

[Kestrel]

Does anyone know the difference in ballistics for the Marlin 1895 .45-70, with the 22" barrel and the 1895 Guide Gun, with the 18" barrel? (FPS)

I'm wondering if the additional 4" of barrel makes much difference in the .45-70, especially using some of the stout premium loads on the market.

Thanks.

 

[Mossyrock]

Figure 25 fps loss per inch of barrel (more or less).

 

[RugerNo]

Actually, close to 15fps per inch with the high expansion ratio of a 45cal barrel. With the 45-70, the only reasons for long barrels are black powder or a better sight radius.

 

[MachIVshooter]

Some testing I did with hot 405 gr. loads proved some significant variation. From my standard 1895, MV was 2015 FPS. From my friends guide gun, velocity was 1938 FPS. That equates to a fairly substatial drop in ME, from 3652 FPS to 3378 FPE. I'll take my full length.

The difference may be less with low-pressure factory loads, but we did not test them.

 

[JohnKSa]

Mach4shooter,

That's 77fps less with the shorter barrel which works out to a bit less than 20fps of loss per inch of barrel. The problem with the kind of testing you did is that you might see 50fps difference in two "identical" guns with the same length barrel.

In other words, you know the velocity difference between the two PARTICULAR guns you actually tested, but it's hard to say with a high degree of accuracy just how well your results will apply to two different guns. It's probably safe to say that the longer barrel will, on average, offer more velocity, but it might be significantly less velocity difference than was apparent in your test.

Very generally speaking, the larger the bore, the less velocity improvement you get from a longer barrel.

 

[MachIVshooter]

That's 77fps less with the shorter barrel which works out to a bit less than 20fps of loss per inch of barrel. The problem with the kind of testing you did is that you might see 50fps difference in two "identical" guns with the same length barrel.

True, but ballistics programs project almost identicle velocity difference. The reason I make a big deal out of it is because it is a significant loss in energy with such large pills. 77 FPS isn't much with a .30-06 and a 150 gr. slug, but the 274 FPE lost on the .45-70 is substantial. New "magnums" are often bought to replace older rifles for a smaller gain.

 

[JohnKSa]

but the 274 FPE lost on the .45-70 is substantial

Nah. It's still only 77fps. Even when you express it in energy, you only loose about 7.5% going to the shorter barrel.

I can't imagine a situation where decreasing the velocity by 3.8% would make any practical difference. In fact, it wouldn't surprise me to find that kind of velocity variation in a single box of factory ammunition.

The only practical reason for the longer barrel is if you're an iron sight junkie. (Like me. )

 

[Cosmoline]

I used to own an 1895G, and I've shot the full length version as well. IMHO the original is better. Velocity is one issue, but recoil is another. Even with porting, the G is seriously painful with hot loaded .45-70. I found the full length 1895 a notch less nasty.