Author Topic: bbl length on underhammers/does 6" matter (Read 761 times)

tomhargrove · « **on:** June 25, 2005, 08:00:45 AM »

i have also been thinking about one of these H&A underhammers would you think that the 26"would be less accurate than the 32" in .36cal i know 6" s is not that much but it does make it a little more suetid for my pack-basket if tied on the side and would there be a great difference in m/v and m/e- got- to -get-one but cant decide the length

ribbonstone · « **Reply #1 on:** June 25, 2005, 08:58:37 AM »

Considering the powder charges typicaly used in a 32 or 36, don't believe that 6" of barrel length is going to make a significant ballistic difference...will be less vel., but not enough less to put the gun out of it's use-class.

May miss the sight radius.
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Don't have reproted 36cal. numbers, but do have the following as a guide:
.32cal. 30gr. 41.5" barrel = 2081fps
.32cal. 30gr. 25" barrel = 1871fps.
That works out to less than 13FPS per inch.

Bot really fair as it isn't the same barrel being shortened...even if two barrels were identical in length, wouldn't expect them to give idential vel. readings....but it should ball park the loss of vel.

Something like 20FPS in .36 wouldn't be far off...call it 100-120fps for that 6" loss.

OR you can figure the old way (for black powder guns only)...that the loss will be about 1/2 the percentage of change. Pretty good rule of thumb, as the 2" lost from going from 20" to 18" is a larger percentage than if going from 32" to 30".

tomhargrove · « **Reply #2 on:** June 25, 2005, 09:51:35 AM »

thanks for the tech/info so im guessing a squirrel wont know one way or the other how fast the ball was going when it hit him , this is about all i want to do with it , :grin: kind of a small companion peice for overnight treks or canoe trips and the 6" off will make it more portable now that i know it not going to take away to much of it`s ballistic value thanks again. :shock:

BS · « **Reply #3 on:** June 25, 2005, 10:49:24 AM »

You may loose so sight radius, but the shorter barrels carry much nicer. Most of my barrels are less tahn 28". Took a 32" 54cal to Colorado elk hunting, when I got back, the barrel got cut off.

I like 27" a nice even number, for a guy who thinks 26 is short and 28 is long.

For the lost sight radius, I shoot peep sights.

Slamfire · « **Reply #4 on:** June 26, 2005, 01:26:10 AM »

My Numrich "Buggy Rifle" has a 20" barrel, makes it real handy for canoe, or packing. You'll have to learn to load while youj sit though, it's way to short to load standin' up. :-D

ribbonstone · « **Reply #5 on:** June 26, 2005, 11:52:12 AM »

Kind of shamed me into it, haven't shot that H&A underhammer .36 in a long while so I took it out for a fast range visit today. 32" or heavy (.94") untapered barrel....a bit heavy...and add that the prvious owner decided to add a full length fore end to the muzzle.

Useing the 125gr. bullets sized to .354" (and now with a cupped base), 40gr. GOEX FFFg, CCI #11's produced an average of 1603fps. Can go higher, but accuracy doesn't improve. If I go lower, accuracy gets worse probably becasue I am relying on the burning powder to slug that bullet up to goove size.

Not bad off a bench...but with that long barrel it's balance point is actually ahead of your left hand on the fore end. IF I were to carry this one out hunting much, it would end up about 26" long.

Does need to be patched every 3rd shot to keep fouling reasonable and accuracy up to par.