hypervelocity 22 lr research

[tech30528]

Ok so the order finally arrived. Got 500 rounds. I'm in the process of weighing them now. This is something I do with with all the ammo I test (except for the match grade stuff because of price I didn't buy enough of each for statistical measurement) I'm about half done with the brick and it is looking pretty good. The median is 51.7 grains (total weight of case, primer, bullet and powder) . Here is the theory here. These rounds are Eley primed, so we are going to assume the primer loads and brass are consistent. If the bullets are consistent than the weigh difference from one to another would be powder which would translate to speed differences. It's as close an estimation as I can make and still fire the bullets.

So far the spread on these rounds is from 51.3 grains to 52.1 grains (and so far only one of those) . The vast majority are running from 51.6 grains to 51.8 grains which is fairly typical. For my favorive AR Tacticals the median is 51.3 grains with most of them running 51.2 to 51.5 grains. For shooting purposes what I normally do is shoot the more common weights as they are separated and use the less common weights on either end as pistol rounds.

I'll finish weighing these out tonight and weather permitting get some downrange tomorrow after church.

 

[Orion8472]

Coming into this discussion, late, and slightly out of my league.

I'm a novice .2lr shooter, so bear that in mind. I have a 10/22 with a Clerke 16" bull barrel with the Bentz chamber. It will not accept Stinger length casing rounds. I went with what I considered to be "the next best thing" when looking for a faster round. I use CCI Velositors and have gotten fairly impressive groupings with them at 100 yards. ~ 1 1/2 inches roughly. I haven't been out with it in a while and am having a bit of custom work done and plan on retesting it after the work is done. Just my 2 cents.

 

[230RN]

Hm. One index of the value of a thread is how many times I have to look up something someone mentioned because I didn't know it before. Never heard of a Benze chamber, so I looked it up:

http://www.riflebarrels.com/products/chamber_info.htm

From that site,

1.The drop-in barrels we manufacture for the Ruger 10/22 are chambered with a "Bentz" semi-auto match reamer and it is not as short as the other match reamers we use. Unfired ammo can be extracted from this chamber. We do not recommend using CCI Velocitor or Stinger ammo in the 10/22 barrel. Also see this FAQ on the subject - Click Here. (URL of that "Click Here" is http://www.riflebarrels.com/faq_lilja_rifle_barrels.htm#stinger

So from that link to their FAQ section, I find:

Q. Why do you recommend not using Stinger and Velocitor ammo in 10/22 barrels?

A. We chamber our 10/22 drop-in barrels with a Bentz semi-auto match type reamer. This type chamber is shorter and tighter than a standard sporting type chamber. As a result higher pressures are developed when the longer Stinger and Velocitor type ammo is fired in a shorter match type chamber. The end result can be a blown extractor slot in a 10/22 barrel with a match chamber. The following is from CCI:

"Where the problem resides is that the Stinger case is 0.100" longer than
a Long Rifle case, their chamber is not made to ANSI Sporting Chamber
dimensions, it's shorter, the Stinger case is then engraved by the
rifling and increases pressure. See the Warning on the back of the
Stinger packaging, ensure you know which chamber your rifle has. If not
an ANSI Sporting Chamber, do not use Stinger."

(I note the variations in speling of "Benze" and assume they all mean the same thing.)

So I am confused, Orion8472. Why are you using Velocitor ammunition?

Terry, 230RN

 

[Orion8472]

I spelled it wrong, but fixed it in my post. After your post I did another look into what I have [was told by someone else it was a Bentz chamber]. My barrel isn't a Lilja and I may have mispoke on it having the Bentz chamber, but just don't know at this point. Any information on Clerke barrels doesn't mention "Bentz". It definitely doesn't take the Stinger casing.

The Velocitor has a standard length casing, so am not sure why it would be included on that Lilja information page. I've had no issues when using Velocitors.

If true, I was comletely unaware of that information and will look into it further with my [excellent] gunsmith. But again, I don't see how the Velocitor can have the issues that the Stingers have with the Velocitor's standard length casing.

 

[tech30528]

Got a few rounds downrange today and ended up with a loose scope mount. Dammit. So today's results are inconclusive. Not even going to try to fix that here, I'll take it in to the shop this week and take care of it. Very strange. I have the same mounts on both rifles I was using today. Never had a problem with one, the other has given me problems on several occasions. Same rifles, same rails, same rings, same bottle of Loctite.:banghead: