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Pete Wass

Pete Wass

Well-known member
tested 5 lots of ammo on Wednesday of this week. Before I tested I measured the "working length" of each lot and recorded the lengths of each lot. The result was the lot that had the lest amount of variation in length (.004" ) shot distinctly best . Not good enough though for me to consider buying any of it. Working length, alone, does not seem to be the entire answer.

Pete
 
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Did you ever stop and consider that it has little to do with length varience but OAL in a range for your given chamber?
Certain chambers preffer certain OAL's.
 
Oal?

tim said:
Did you ever stop and consider that it has little to do with length varience but OAL in a range for your given chamber?
Certain chambers preffer certain OAL's.
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Tim,
Seems to me that the variance in OAL would be the product of bullet seating depth and is sure to vary to a certain degree in any product that is mass produced. And, surely it would vary from one machine to another due to how long that machine had been operating since it's last renewal, overhaul, calibration, or whatever Eley/Lapua/RWS/etc. desires to call it? I would think that case length would be more of a "constant", measure wise, than bullet seating depth, when it applies to OAL. Whaddaya think? V/R, Bill
 
William Smith said:
Tim,
Seems to me that the variance in OAL would be the product of bullet seating depth and is sure to vary to a certain degree in any product that is mass produced. And, surely it would vary from one machine to another due to how long that machine had been operating since it's last renewal, overhaul, calibration, or whatever Eley/Lapua/RWS/etc. desires to call it? I would think that case length would be more of a "constant", measure wise, than bullet seating depth, when it applies to OAL. Whaddaya think? V/R, Bill
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I believe it tends to be more about cases, however that is not the point I was trying to make.
It is about the fact that there are lots that are short and lots that are long. Within the scope of my lot testing, I've had 10 thou. spread.
We know throats foul, we know at some point accuracy trails off. The rate of one impacts the other. OAL may impact the rate of this IMHO.
 
Oal

Tim,
You may be right, however, I don't know for sure! I do know that when accuracy starts to dwindle, out comes the brush and then some ISSO. If C/L ring removal doesn't help in the accuracy dept. then it's time for the borescope and a barrel check. What about headspace variance, could that be a factor also? Bill
 
There are a couple very good smiths of the opinion that the differance between matched OAL to a chamber vs mismatched, may result in accuracy degradation durring a card.
I'd suspect thats why the WLM pushes for the measuremen to be labeled on the box.
Here's a test for you, get your best ammo and then something either a lot longer or shorter. From a clean barrel, run about 1/2 box and scope the throat, cleaning between lots. I bet you see a material differance in fouling in the throat from one to the other.
It seems some chambers handle several lots and some are rather fussy. I believe MI barrels get real tempermental in this regard but not owning one, it is what I've been told.
 
I measured several

Known good lots today and found no relevance between them with regard to "Working Length". What I think is, good shooting ammo is good shooting ammo, within limits of course BUT does not have any significantly long or short OAL's and the reason to measure. I have found all sorts of stuff during my measuring, Some with no driving bands and even one round nose in a box of Black Box last year.

Pete
 
Pete Wass said:
Known good lots today and found no relevance between them with regard to "Working Length". What I think is, good shooting ammo is good shooting ammo, within limits of course BUT does not have any significantly long or short OAL's and the reason to measure. I have found all sorts of stuff during my measuring, Some with no driving bands and even one round nose in a box of Black Box last year.

Pete
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Really. So apparantly the well accepted notion of lots of ammo that does not much in one particular gun, yet excells in another is likely a fabricaction, misunderstanding, or has'nt yet landed on planet Wass?
 
I have no dog in this, but I do have a statement to think about. There are those magic lots that seem to shoot extremely well in every single gun you shoot it in.................now, would someone explain that to me in regards to working length?
 
Oal?

John,
Seems as though Tim has all the answers and a bone to pick with Mr. Wass. I was trying to pick up some ideas on finding good ammo without spending a small fortune testing. I had a "magic" Lot of Black box Eley in 2010, Lot # 4243 and it shot in every gun that I had, Sporter and heavy gun. I won 17 HOF points that year. Am still looking for another of the same performance level. Was hoping Tim had a clue, but he's to busy digging at Pete. Bill
 
What I have found

probably makes no sense to anyone else but that does not matter to me. I have had pretty good results with my methods of testing to date so I'll keep going with it. The Working length theory, to me, makes little sense at this point. It appears to me that either a particular lot will shoot in one's barrel or it won't. Otherwise all we would need to do is measure the working length.

I have found plenty of ammo that my Rock Creek likes but not the Wilson on my Myers. It seems to prefer the # 5 machine stuff but I found two lots of Center X last year it liked as well. Not so this year, so far. Trouble is, there isn't much Lapua available to test. It would be nice it that would change.

Pete
 
Carp said:
I have no dog in this, but I do have a statement to think about. There are those magic lots that seem to shoot extremely well in every single gun you shoot it in.................now, would someone explain that to me in regards to working length?
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Reread #7. Some guns and some lots tend to be very tolerant, I guess. I ve also seen and know a couple smiths that say some are very picky on the OAL deal. Probably driven by barrel configuration and dimension.

Thumper, i believe you got nice direct, polite answers to your questions. Don't see anybody else chiming in. Remember, I'm giving a little color comentary to pretty much the exact same thing the great one from the midwest has been harping on without all the misdirect. You think these guys that suddenly developed all manner of OAL guages did so cause they got nothing better to do? As always, you got Pete to fall back on. Good luck.
 
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Oal

Tim
Got the answers you gave and mostly understand what you are saying with the exception of the case length. I still think that their measurement would be more consistent than the bullet seating depth, but then again I have been wrong before. I just measured the OAL of a box of Eley Black box Lot #1114-2165, avg. difference from shortest to longest was .004. I have only tested it in my heavy gun when the outside temps were in the high 30's and low 40's and it shot above average then. I'm hoping that by the Crawfish shoot in April when the temps will be in the 80's that it will shoot even better and more consistent. Will let you know my outcome. As far as listening to the WLM goes, well that's of a different story all together. After 26 years of active duty in the Navy, you can imagine that I've heard maybe not all of them, but the majority of them tall tales. He really needs to hire a PR firm. The only one who praises himself more---lives in the White House.
V/R Thumper
 
Well yes and no, i assume you know I'm not exactly the pres. Of the local fan club. That said, no denying he can build a gun and as to this topic he's likely right. As Carp indicated, probably not all cases, but many, and when in doubt, it's a good place to start for lot selection.
As to seating or cases....could be a bit of both but since it it still OAL what differance would it make, still longer vs shorter.
 
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Measuring a bullet

"OAL" may not be that important.
Case length may not be that important.
Rim thickness may not be important. (head space)
Barrel internal dimension may come into play.
barrel external dimension may not.
Chamber depth Will!!
Carbon build up WILL!!.

So what is this magic measurement ?
 
Measurement?

Gordon,
Don't know what the magic number is, however, the sporter that you re-barreled for me and the Calfee 40X that you re-barreled both shoot great, so whatever measurement that you deem appropriate seems to be the correct one. Just keep doing what you been doing and all will be right. There are just to many variables to be able decide on one number versus another, especially with the number of barrel manufacturers that we deal with. "If at first you don't succeed, skydiving is not for you"! Thanks Gordon. V/R, Bill
 
This thread raised a few questions in my head.

When I shoot CF benchrest, seating depth and bullet jam are often quoted as being factors that affect accuracy.

My favourite rimfire rifles both have tight (match?) chambers such that some ammunition (eg: CCI Stinger) cannot fit. (Anschutz M54 & Izhmash KO-2 Biathlon)

So if bullet jam is so important for a centerfire, is it just as important for a rimfire and would bullet length affect this.

What affect does this have on accuracy?

Still learning.

* doghunter *
 
Tuners.............???

Excuse me... I`m not an ara shooter.... yet....... hope to be someday.....
isn't a tuner of value which making different lots of ammo shoot in a particular gun.....?????
 
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