Low resolution pictures just travelled to Texas. When you want more details I'll try to make some pictures in daylight, just ask.

Aloys, the pictures were great! Thanks!! I finally found some a jackpot of information on the web on the Marlin 39.

www.thehighroad.us/sho...=marlin+39

Ok, here is my plan. I'm going to take my Marlin out to the range and do a 10-shot string for velocity measurement with its stock 24" barrel. I'll then cut about 3" off the barrel with a hacksaw. Repeat the velocity measurement, cut 3 more inches off and repeat again. I think I want to go for 18 inches but may cut finer as I seek a comfortable balance. Post velocity measurements, I'll have the barrel recrowned and a dovetail added for the magazine. This will be a true test of barrel length vs velocity because its all from the same barrel vice barrels from different manufactures with different bores and rifling. The only ammo that showed optimum performance at 16 inches was the CCI Green Tag. I don't have any more and I'm not sure its readily available anymore. I think I'll use the Federal Bulk and Target, Winchester Bulk, RWS Target, and Aguila. That will be 150 rounds. Suggestions?

Won't you have to at least deburr the muzzle after cutting? Should be an interesting test.

SJ, buy a reamer, cut a new .22 chamber in the 3" barrelpieces and fix them inside another cartridge as a cal 12 shell or put it on a lathe to give the outlines that fit in your revolverchamber. A nice thing for traphunting or even giving the last extra headshot.
That's some extra fun and your environmental foothprint will become a little smaller

Aloysius wrote:

cut a new .22 chamber in the 3" barrelpieces and fix them inside another cartridge

Interesting concept. Guess the bore would have to be offset to make it work.

I committed to this project today! I pre-cut the barrel to make it easier to cut-off barrel sections at the range. Hopefully, I'll have some velocity data soon - all from the same barrel. The extra cut in-front of the dove tail will allow me to keep the dovetail on the lower section of the barrel which will make the gunsmith's job easier when he relocates it.

I'm thinking 18.5" to 19" looks about right with the front stock. Any shorter and it will start to look stubby.

Very nice experiment, Slim. It will be interesting to see your results. Will you be trying both standard and hyper-velocity ammo?

44marty wrote:

Will you be trying both standard and hyper-velocity ammo?

I've decided not to buy any more ammo. I must have X000+ rounds already. I plan to use Federal Bulk and Target, Winchester Bulk, CCI Mini-Mag, RWS Target, and Aguila. That covers the range from highest to lowest velocity from my last test. This time, all the data will be from the same barrel.

Maybe I can get out tomorrow morning.

I decided to start a second post with the results of today's assessment.

.22LR Velocity vs Barrel Length - Take 2