Question

[dgeesaman]

A fellow that I shoot with from time to time, has had several bricks like this. It's sad to watch it happen at a match. JME. WD

A guy at my club bought two cases of ammo that shoots lights out but about one shot in fifty drops low. Can’t remember if it’s Lapua or Eley. Terrible shame.

 

[flatlander]

That's what I hate about having to 'buy blind' in today's market. As recently as early 2019, I was able to order in lot samples from wholesalers and test as many lots of Center-X as they had left in quantity. Even if I wasn't able to find that 'magic' lot, I didn't have to risk a lot of money buying a case of CX without testing in my rifles first.

FWIW, the 52Ds I own generally shoot Eley Match better than any of the SK or Lapua I've tried in them...

 

[dgeesaman]

That's what I hate about having to 'buy blind' in today's market. As recently as early 2019, I was able to order in lot samples from wholesalers and test as many lots of Center-X as they had left in quantity. Even if I wasn't able to find that 'magic' lot, I didn't have to risk a lot of money buying a case of CX without testing in my rifles first.

FWIW, the 52Ds I own generally shoot Eley Match better than any of the SK or Lapua I've tried in them...

To be clear, if this was in response to my story about the two cases with a few dozen bad rounds, they were lot tested in advance. But a bad round per box is often going to slip past lot testing, which makes it especially unfortunate.

On one hand, everyone is subject to the same basic constraints so as a competitor it's just another element of competition preparation. On the other hand, it's really hard to grow rimfire competition when the battle is partly won/lost months or even years ahead of them joining.

 

[Hi-NV Shooter]

To be clear, if this was in response to my story about the two cases with a few dozen bad rounds, they were lot tested in advance. But a bad round per box is often going to slip past lot testing, which makes it especially unfortunate.

On one hand, everyone is subject to the same basic constraints so as a competitor it's just another element of competition preparation. On the other hand, it's really hard to grow rimfire competition when the battle is partly won/lost months or even years ahead of them joining.

IME if you were to check. The OAL of the lot you will find that there will be a majority that will sort within 0.002-0.005 with a few that will be 0.010+ or longer or shorter this is where those fliers and droppers are coming from.

Lee

 

[MrG52D]

Ammo like we are speaking of is one reason our non-sanctioned club went to a 275-scoring system. This allows for a miss or two to be made up over the course of the target. Finding ammo without issues in today's market, is tough. So, we look for ammo that can produce a high number of X's, if it has a flipper or two, it's still good. Now when I shoot IR50, that requires good ammo. Needs to hold the 10 ring and produce a good X count. I buy test lots in bricks, what I don't like gets sold, even if I have to take a loss on it. Just the cost of doing business.

 

[dgeesaman]

IME if you were to check. The OAL of the lot you will find that there will be a majority that will sort within 0.002-0.005 with a few that will be 0.010+ or longer or shorter this is where those fliers and droppers are coming from.

Lee

I can ask if they tried that but these guys aren’t rookies and they have calipers and rim thickness gauges and stuff like that. If there was a way to sort them out they’d probably have done it and the story would have been about the work it took instead.

 

[Hi-NV Shooter]

I can ask if they tried that but these guys aren’t rookies and they have calipers and rim thickness gauges and stuff like that. If there was a way to sort them out they’d probably have done it and the story would have been about the work it took instead.

That may seem like they aren't, but calipers won't work and rim thickness? might help with firing pin hit.
first if you know how your chamber is setup. as example my barrels are all done with a Nevius reamer for 0.030-0.040 engraving off the Ogive. without this knowledge everything is a guess.

I use a MK-3 gauge which measures OAL from the Ogive as measured from the front of the case rim. the part that will seat against the breech face. I found OAL of from 0.695-0.720 will shoot the best in all four of my Benchmark 3G barrels. when you sort them in groups of only 0.005 spread, they become very predictable.
I have seen lots with lengths that are just all over the place and these are not match usable ammo. good lots will have lengths that will sort and have only 3 different lengths. with a majority that will be over 70% within 0.002-0.005 my most recent CX has out of 500 rds. 350 which sort with a spread of 0.005 the number reads 0.700-0.705 100 rds. are 0.690-0.695 and 50 have a mix of 0.680-0.740 it is these 50 rds. where it would give a flier or dropper generally the longer lengths will drop out and score an 8 or7 versus a 10 or 10X shorter will give the highfliers. this has been my experience sorting by OAL.

Lee

 

[dutch14]

HI-NV if I follow what you are saying the rds longer than 0.700 to 0.705 give low fliers in the 8 ring and rds shorter than that will give high fliers in the 8 ring? Out of 500 rds you expect to find 50 flier rds?

 

[Hi-NV Shooter]

HI-NV if I follow what you are saying the rds longer than 0.700 to 0.705 give low fliers in the 8 ring and rds shorter than that will give high fliers in the 8 ring? Out of 500 rds you expect to find 50 flier rds?

For a lot that was bought blind that is not bad. a really good lot will have less than 30 rds.
of the 50 rds. I had 3 groups of different lengths. only about 10 were in the 0.735-0.740 the rest a mixture of from 0.680- 0.685. this little amount would not be something I would use say in a match not enough to shoot 3 cards.
FYI I only sorted 1 brick out of a case so it may very well get better with less of 0.735-0.740 and even less than the .0680-0.685

Lee

 

[Dusty Stevens]

For a lot that was bought blind that is not bad. a really good lot will have less than 30 rds.
of the 50 rds. I had 3 groups of different lengths. only about 10 were in the 0.735-0.740 the rest a mixture of from 0.680- 0.685. this little amount would not be something I would use say in a match not enough to shoot 3 cards.
FYI I only sorted 1 brick out of a case so it may very well get better with less of 0.735-0.740 and even less than the .0680-0.685

Lee

What does that sorting tool look like?

 

[gunsandgunsmithing]

What does that sorting tool look like?

I've used a barrel gizzy. Whatever you wanna call the bbl cutoff with a reamer run in, to the same depth on a rf or otherwise account for the length difference and use it strictly as a comparative tool. If same length, you can use it to establish case protrusion that worked best or to set up future chamberings with the same chamber length.

 

[1911nut]

What does that sorting tool look like?

G3 Rimfire Rim Thickness Tool and Base-to-Ogive Length Gauge « Daily Bulletin

Gerry Gereg makes two precision tools that let rimfire shooters pre-sort their ammo for improved accuracy. The first tool, the G3 Rimfire Thickness Gauge, lets you sort rimfire ammo by rim thickness. This tool clamps to the jaws of your calipers and is very simple to use. Just slide a cartridge...

bulletin.accurateshooter.com

Ive sorted thousands of CenterX. I didn’t find a length that shot smallest in my gun but shooting sorted similar lengths I had way fewer fliers. Some lots varied in rim to ogive 0.006-0.009”. Sorting out the longest and shortest reduced the high and low shots. I didn’t look at whether long rounds went high or low. There’s more work to do but sadly it was 23 below this morning so I won’t get to the range for a while. It appears the gauge has been discontinued.

 

[tmwinds]

Poor man’s rim thickness gauge using a .223 fired case. Measure the length of the .223 case and zero the calipers. Insert the .22 rim fire and measure. You have the rim thickness. I just measured a box of Center-X and all measured .0435 plus or minus .0005.

 

[USMCDOC]

G3 Rimfire Rim Thickness Tool and Base-to-Ogive Length Gauge « Daily Bulletin

Gerry Gereg makes two precision tools that let rimfire shooters pre-sort their ammo for improved accuracy. The first tool, the G3 Rimfire Thickness Gauge, lets you sort rimfire ammo by rim thickness. This tool clamps to the jaws of your calipers and is very simple to use. Just slide a cartridge...

bulletin.accurateshooter.com

Ive sorted thousands of CenterX. I didn’t find a length that shot smallest in my gun but shooting sorted similar lengths I had way fewer fliers. Some lots varied in rim to ogive 0.006-0.009”. Sorting out the longest and shortest reduced the high and low shots. I didn’t look at whether long rounds went high or low. There’s more work to do but sadly it was 23 below this morning so I won’t get to the range for a while. It appears the gauge has been discontinued.

yeeup.. that'd be it

 

[gunsandgunsmithing]

Correct me if I'm wrong here but rim thickness gages have nothing to do with where/when the bullet contacts the lands.

 

[Tony K Harper]

Correct me if I'm wrong here but rim thickness gages have nothing to do with where/when the bullet contacts the lands.

Rim thickness primarily effects headspace. A thinner rim would allow the bullet to go further into the lands than a round of the exact same working length with a thicker rim. But even then, it would be minimal.

But as you said the gage has nothing to do with this other than to provide a way of measuring the rim thickness on the round.

 

[MUP]

Couldn't a comparator accomplish the same? Not trying to be a jerk, just genuinely asking bc I do have a comparator set and was going to start measuring OAL of my rounds now to see what difference it will make. Or, does the measurement need to be from the case rim that seats in the chamber side to the ogive?

 

[1911nut]

Here’s something:

Sorting Rimfire Cartridges by Hawkeye Wizard

This resource was created by Hawkeye Wizard aka Ron Elbe. Mr Elbe is an accomplished ARA shooter. He ranked First in his home state of Iowa in the ARA Outdoor Unlimited class in 2012, 2013, 2014 & 2015 and was ranked 4th nationally in 2014. Click on each of the chapter headings to navigate the...

www.rimfirecentral.com

 

[Hi-NV Shooter]

Couldn't a comparator accomplish the same? Not trying to be a jerk, just genuinely asking bc I do have a comparator set and was going to start measuring OAL of my rounds now to see what difference it will make. Or, does the measurement need to be from the case rim that seats in the chamber side to the ogive?

Great question the MK3 gauge is unique in that is measures off the Ogive. here is how it does it. the cup that rests against the bullet rides inside the body of the gauge with a very low-tension spring it is preloaded so when you insert a round it will move up and move the indicator stem to give the reading. I use a digital indicator for more accurate measuring.
It should be noted that Bill Calfee at one time advocated that Eley should put the OAL of the lot and not the speed. he mentioned a shooter could simply match the OAL to the barrel that it will shoot good in.

Lee

 

[Hi-NV Shooter]

Here’s something:

Sorting Rimfire Cartridges by Hawkeye Wizard

This resource was created by Hawkeye Wizard aka Ron Elbe. Mr Elbe is an accomplished ARA shooter. He ranked First in his home state of Iowa in the ARA Outdoor Unlimited class in 2012, 2013, 2014 & 2015 and was ranked 4th nationally in 2014. Click on each of the chapter headings to navigate the...

www.rimfirecentral.com

before Ron came out with this post on RFC, I had been using the tool and his findings further validated what I saw.

Lee