Should I shorten my barrel to 16 1/2 inches?

[Goofycat]

I purchased a used Clark Special a year ago for ground squirrels. It is a .920 SS Clark barrel and is very accurate. The problem is that the barrel is heavy, making me think that it might be nice to shorten the barrel a bit. Clark says there will be no problem to shorten it to their recommended 16 1/2' length and that accuracy won't suffer, since the bullet reaches maximum velocity prior to exiting the shorter barrel.

I don't want to place a carbon fiber or fluted barrel on the rifle because of cost, and I like the stability that the present SS barrel provides. The only thing I don't like is the weight.

My question: are there any drawbacks to a shorter barrel as far as accuracy goes, and would there be any other problems, such as increased noise? Clark quoted me only $50 to shorten and recrown the barrel.

 

[NateHaler]

I'm thinking your question will find answers here: http://www.rimfirecentral.com/

 

[GermanS1]

Barry, I shoot a lot of Smallbore prone, the accuracy standards there are very high. My barrels are all in the 18' to 19' range on Anschutz 2013 actions. I cut them from 27' for the same reason you're describing, less weight. The most pleasant surprise I got was that accuracy improved in all cases. I use a 16' bloop tube to maintain a long sight radius but that doesn't really affect anything else. Cut with confidence.

 

[Goofycat]

German, I forgot to include a possible drop in muzzle velocity in my original question. Have you or anyone else experienced any drop in MV after barrel shortening? Clark reports no drop in accuracy by shortening the barrel to 16 1/2 inches, but what about velocity?
I use Winchester Power Points for ground squirrels. I used my Pact to measure it several years ago and IIRC the velocity was around 1300 fps. If the MV drops as a result of my anticipated barrel shortening, I will just keep the existing 21' length.

Clark reported that the maximum velocity is reached below 18' and that barrels any longer merely slow the bullet due to the additional friction. I am talking about rimfires, and not centerfires, of course. When you shortened your barrel, did you measure the pre and post-cutting MVs? The reason I am concerned is that I shoot in wind at times and want all the MV I can get, even though accuracy might not be affected by the shorter length.

 

[GermanS1]

Barry, MV will increase a bit, but that's actually a bad thing for wind drift. Rimfires are really different animals, minimum wind drift is achieved with an MV of 950 to 980 fps, any faster and they start to get into the transonic region which increases drag dramatically and wind drift increases. This is very counterintuitive to a centerfire shooter, but it's the way subsonic stuff works.

There's a very detailed study on this from BRL, I'll see if I can dig up a copy.

 

[GermanS1]

Found it -
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA229713&Location=U2&doc=GetTRDoc.pdf

 

[RichinKansas]

Depends how you shoot it. A little weight can give stability and slow muzzle motion. If the rifle is so heavy as to make your muscles quiver, less weight might be good. I believe German shortens his to save weight because he is in position for near 20 minutes numerous times in one shooting session.. His gun is still heavier than yours I would bet. If you have to carry it a far piece before shooting lighter might be better too. But there is a risk to cutting and re-crowning a good shooting barrel. The new crown might not be as good, Also if the barrel is cut at a loose spot it might not shoot as good. Also if you are shooting a distance of 100 yds or so you will see a few ten's more wind drift not much. More velocity has nothing to do with better accuracy. That is why good match ammo is slow and not high speed.

 

[Goofycat]

Thanks, German and Rioh. I always wondered why the match ammo was considered more accurate than the higher-velocity cartridges. You have explained why. Also, thank you for advising of the possibility of a change in accuracy due to a new crown. Since the rifle is quite accurate,at least for small varmint hunting) I will think twice about having the barrel shortened.

Shortening the barrel might reduce the weight by a pound; most shooting is from a bench rest situation; I don't use the rifle for much walk-about shooting, so this would also be a factor. As you may know, ground squirrels are quite small, but this particular rifle can nail them at 100 yards or more, depending on the wind and how much caffeinated coffee I have prior to a shoot.

Thanks again for your great input1

Barry

 

[Hammer47]

Found it -
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA229713&Location=U2&doc=GetTRDoc.pdf

German...I understand the subsonic accuracy idea but my question is why is the high speed 22 ammo always more forgiving in the vertical for extreme distance shooting with the 22 rimfire? I have done a lot of group shooting over windflags on a protected range with known scope/rifle parings and at 100 to 300 meters the supersonic ammo always is superior to the subsonic and the problem is always the vertical. Windage seldom suffers with either of the ammos. This came as quite a surprise to me as I thought the opposite would be true. Regards... Gary