TargetTalk

Has anyone got any tips about testing ammunition on a Pardinin PGP 75 free pistol?

I was planning to use a vice to hold the pistol, but were should I clamp it?
I don't want to clamp it in the barrel, I was thinking in the wooden part in front of the trigger guard.

What do you sugest?

Yes you can clamp on the barrel, with soft jaws. Remove the wooden grip and clamp in front of he trigger unit, be sure you can smoothly function the bolt and the trigger set. With the Pardini you need to be careful not to twist the clamped action while closing the bolt. Factories test this way all the time usually with lead jaws in the vice.

As Greg has suggested clamp the barrel. I alway test Free Pistols like this and have made myself a couple of hardwood blocks each with a shallow vee in them for holding the barrel. They hold nice and firm and they don't damage the barrel. With good match grade ammo you should expect 12-15mm groups (that's centre to centre measurement).

I made a set of adapters for the club's Ranson Rest the last time I tested. Clamping the barrel is just as good, maybe better. Just be sure to test at 50M/Yds. Accurate ammo at 25 meters can deteriorate at the longer distance.

Larry

My question regarding clamping the barrel, is that clamping the barrel might not disturb the pistols natural barrel vibration, and therefore increase the grouping size?

tqb wrote:My question regarding clamping the barrel, is that clamping the barrel might not disturb the pistols natural barrel vibration, and therefore increase the grouping size?

It's a .22cal free pistol with a 10-12" barrel, so barrel harmonics are probably not worth worrying about. If it was a rifle, a centre fire in particular then yes harmonics need to be considered.

I wouldn't worry about it, if it did effect the result I suspect that it would be for the better as the clamped barrel is dampened.

A barrel clamp for testing ammo in a free pistol removes just about all the variables and is the only valid and reliable way to test the ammo in that particular pistol.

tqb wrote:My question regarding clamping the barrel, is that clamping the barrel might not disturb the pistols natural barrel vibration, and therefore increase the grouping size?

Because you are ammo group testing the results will still be relative, the good ammo is still good and the bad still bad.
I made barrel blocks for a Morini milled out of Polyethylene (cutting board plastic) to fit a machine rest. It fitted the front of the frame and about 4" of the barrel, grip remained on and loading was normal. Worked just fine.

Original query:

Has anyone got any tips about testing ammunition on a Pardinin PGP 75 free pistol?

Here's my question: Are you searching for
A. the ultimate small-group potential of the ammo (and as dozens of posts have reinforced, only one particular lot at that), or
B. ammunition that gives YOU good results?

If the answer is A, go nuts. Clamp your barrel (sink it in a block of concrete if you think it will help), and duplicate what you would do at Eley's test range. If you answer B, it's much simpler. A solid bench with good sandbags will tell you more than you'll ever need to know. Given the large human variables in pistol shooting, I suggest this method will give a closer real world match to your results shooting your pistol offhand.

William makes an important point. You can use a rest to weed out ammo that your pistol doesn't like, but how the ammo "feels" is also important. You might find that ammo with more recoil groups better with the barrel clamped, but it's likely to shoot worse when you are holding the pistol.

Two other issues with ammo selection are: A) how well does it mechanically fit the chamber, and B) how clean is it.

PGP75's have tight chambers, and some ammo will be too tight to chamber easily, or will fail to extract if the chamber isn't kept spotlessly clean. I keep a right angle brush handy to give mine a quick scrub if it gets tight, and then pull a patch through the bore with a "patch worm":

http://20-20.8m.com/patchworm.html

I've machined a bending jig, and have made a whole raft of these for the MIT team:



(Note: Bownells has cheaped out, and these are no longer nearly as "bristly" as they once were. I'm searching for alternatives (2/20/22)

If a case does get stuck, you can usually pop it loose with a fired brass. Push the open end of the brass down vertically over the rim of the stuck round, and then lever the top of the fired case forward.



The same approach works with many other free pistols, but I've mostly had problems with stuck rounds in the PGP75, especially with Federal 711B, which is my preferred ammo. The design of the extractor on the PGP is a bit less positive than on many other free pistols.

Thanks Gwhite.

I was some times having the same problem with bad extraction. I used a cleaning rod to remove re casing, but your idea seems more practical.

I will try the vice and the sand bags to try and select a ammo good enough for training and another for matches.

Currently I'm using Topshot sold by frankonia (3,5€) a box (50 rounds), and if they perform as good as they are doing in normal shooting, I'll use them for training.

For matches I was thinking about using Eley Match (11,9€ a box), but I wanted to confirm if this ammo is indeed superior and if if is worth the extra cost performanced based.

If at all possible, you want to train with the same ammo you shoot for matches. At a minimum, you want to find ammo that has the same perceived recoil. Hopefully when you do your testing, you can find some ammo that is both economical and accurate. Some people have discovered that their pistol prefers really cheap stuff, which is great.

One thing you pay for with high end stuff is 100% reliability. That is essential for some disciplines like rapid fire, but not quite as critical for free pistol. That said, even with fairly economical ammo, I don't think I've ever had a dud in a match.

One more question. Should the ammunition fit tightly or lossely on the chamber?

I mean what is preferable? Lossely or tightly?

Thank You,

With a clean chamber, it should load & extract freely. Beyond that, the tighter the fit, the more consistent the location of the round in the chamber, and (at least in theory) the more accurate it is likely to be.

As a practical matter, I would pick ammo that allows me to shoot at least 70 rounds without any extraction issues, starting with a clean chamber. How tight the round is after firing & how much dirt it leaves behind will vary significantly. Two different ammos may start out the same size, but the one with softer brass will expand more & not contract as much, increasing the likelihood of extraction issues. Cleaner ammo will extract easily after more rounds fired than ammo with excess hard lube and/or that burns dirty.

I've noticed that the Topshot fits the barrel tightly needing a gentle push to fit properly. The extraction starts to fail close to 60 or 70 rounds, but only ocasionaly, rarely failing two rounds in a row.

But the Federal Champion (standard velocity solid) fits loosely, entering without any aid.

I'm still a novice at free pistol, so I can not tell if they are performing very diferently.

But I've gotten rather fond of the topshot ammunition, having adjusted to its recoil or feel in my hand.

Tomorow I'll test in a vice and in a rest (sandbag) the Eley match, the topshot, the federal and the Geco rifle.

Will report afterwards.
Thank You.

Why not use the cheap CCI blue box Standard Velocity like everyone else.

I will test that one too (had forgotten about it), but in Portugal the CCI standard velocity in paper box is 4,5€ a box (and not always avaliable), the Topshot (sold out and probably no longer avaliable in Portugal) and the Federal are currently at 3,5€.

I do like the CCI and even bought a 5000 round batch once. But since I've had dificulty finding it in Portugal, I've saved my last 8 boxes to use in my Pardini SP and CZ 75 Kadet. I know CCI works well on them and haven't tested other ammo thoroughly on them.

But thanks for the idea. CCI is in the bag along with the other brands.

After years of cramming various sized and shaped rounds into free pistol chambers, I'm thinking there are really 2 issues here. The one you all have been talking about is basically chamber diameter. But I think maybe most of the time the resistance that we feel when loading has nothing to do with chamber diameter (how "tight" or "loose" the chamber is), but with chamber length. The resistance occurs when one or more driving bands of the round are pressed into the rifling. So chamber length, and bullet (not cartridge) diameter and length are the critical factors.

Don Nygord told me that he looked at the free pistol as a small rifle, and that top benchrest rifle shooters had told him that at least one driving band of the bullet should be engaged in the rifling before firing, for the best accuracy. So if a round chambers in a free pistol with almost no resistance, according to Don, it's not likely to be as accurate as one that has more resistance. Of course, problems with extracting are a deal-killer for any ammo, but as long as it extracts OK, I wouldn't worry about a little difficulty chambering.

If I'm wrong about this, please someone correct me.

FredB

FredB is quite correct. If you load a round & then extract it from many (most?) free pistols, there will be some evidence that the bullet has engaged the rifling to one extent or another. I drop a fresh round vertically into a chamber as a gauge of how clean it is, and when I first started shooting free pistols, they'd always drop most of the way, and then stop. After lots of scrubbing, I figured out that this was the bullet engaging the rifling, and not anything to do with the chamber's cleanliness.

If you look up the SSAMI spec for .22 long you will find two specs.
The european spec is a tad smaller than the american spec.
So if you use american ammo in a european pistol the chamber will feel tight and you may have extraction problems.
My solution since the 80's has been to run a American Match grade chambering reamer into all my .22's to re chamber.
I have found little or no difference in accuracy (required for pistol shooting) but it means I can load any ammo with no feeding or extraction problems.