First round reload shots from Thursday, high left

[Joe L]

With my new Primary Machine P-10F Match Barrel, which now has about 270 rounds through it...

On Thursday, I anticipated that the first round of each magazine reload would hit high left, just like it did on Tuesday, so I loaded 6 rounds instead of 5 so that I could ignore the first shot and "score" the next 5 as a 5 shot group.  Sure enough, with 4 groups per target, and 3 targets, of 12 first rounds hits, 10 were high or high left, with 7 of the 12 forming a 3-1/2" group!!  Here is a one minute video showing what I found when I got to study the video in detail. 

https://youtu.be/NFxonMT7s2s

I am going to try a stronger recoil spring before touching the barrel, as it is absolutely perfect after the first shot of each reloaded magazine.  Keep in mind that this shows clearly at 100 yards, but is less distinct at 25 yards.  I just think the barrel is still a little tight from being new.  The barrel actually got pretty warm last week during the first few rounds, and it seems to stay cool now, indicating a little less friction after a few boxes of ammo.   

This is becoming quite a project, but a good one, in my opinion.  I'm just glad I had some ammo, good weather, and wanted the trigger time.

Joe

[Boris_LA]

My BE SP-01 was doing this consistently with the original barrel. First round from the magazine was low-right at 50yd. 5 o'clock 8 or 7 ring. Closing slide by sling-shooting it or with slide lock didn't make a difference. It was so predictable, that for a while I was loading for slow-fire 10 rounds and first shot was aiming 11 o'clock 8 ring. I have changed the barrel to new from CZ-usa, fitted it tight and problem seams to got fixed. I don't remember if the same problem was with the original bushing, since I have installed CGW 10X bushing long time ago.

[Joe L]

Boris_LA--Thanks for the response.  I've asked Primary Machine if they have any suggestions and they said it will probably loosen up just a little bit more by shooting it and then should be fine after that.  I have an 18 lb recoil spring coming to replace the 16, and that should help.  I can't feel any slop at the chamber end and I will keep it clean.  The barrel is more difficult to get in and out of the slide than the 75B with a 10X bushing.  I don't mind shooting another couple of boxes through it to see if it clears up without changing anything.  If it doesn't fix itself, I'll send the slide and barrel to Primary Machine and see what they think. 

It is perfect after the first shot, as in, as good as the 75B, 97 B"E", and P-09 pistols, maybe better long term. 

Joe

[Boris_LA]

I have shot both barrels enough to exclude "loosen" from the equation. Recoil spring is the original. I have 10X bushing on three 9mm pistols, but only one exhibit this behavior. 97B with CGW bushing conversion is also free of this problem.

[Joe L]

My P-10C did this but it had 8 mil vertical play at the chamber end when locked up, from the factory.  Slingshot first round and very light oil allowed it to lock up consistently on first round even though a little loose.   I have a new front lock block to try in it, if I want to mess with it.  No problems ever with first round lock up on the P-09, 75B with 10x, or 97B"E".  And none with the P-10S...recently.  The cheese grater lands are a problem with the P-10S factory barrel, however.   

[Joe L]

I've received a heavier recoil spring to try in the P-10F and it is installed.  I think it is 18 lb.  May not get to try it until late this week, however.  I just hope the gun will cycle with the IMI 115 JHP ammo.  I'm thinking the Atlanta Arms ammo that I use when I can get it is too soft for this spring. 
Joe

[Joe L]

I've received a heavier recoil spring to try in the P-10F and it is installed.  I think it is 18 lb.  May not get to try it until late this week, however.  I just hope the gun will cycle with the IMI 115 JHP ammo.  I'm thinking the Atlanta Arms ammo that I use when I can get it is too soft for this spring. 
Joe

Just to follow up after 2 weeks away from the range.  Finally made it to the range on Thursday and shot 100 rounds of IMI 115 JHP through the P-10F with the 18# recoil spring.  The gun functioned perfectly with the IMI ammo, no hiccups at all, didn't have any Atlanta Arms ammo to try, but I think that ammo will cycle fine also. 

However, the heavier recoil spring didn't eliminate my high left first shot from a reload problem.  It may have reduced it a little, however.  But the good thing is that I had maybe 6 good groups in a row loading 6 rounds, slingshot the first round, then ignoring the first shot, and counting the next 5 as the group.   Here are four good groups. 

https://youtu.be/5XD8nX1AtII 

I used a little solvent and a few patches and cleaned most of the copper and carbon then added a little oil and put the gun up for a trip to the mountains of New Mexico next week, where I may try it at 200 yards.  After that, I may send the slide and barrel to Primary Machine and see if they can figure out what is going on with the first round of a magazine.

Joe

[Joe L]

Here is what I am thinking now.  One variable that is different from a sling shot reload and the auto slide cycling reload is the angle the slide makes with the frame.  The amount of freedom here is dependent upon the rail clearances.  In other words, if one pulls the slide back but slightly off to the right as I would do since my left hand fingers are so weak, the slide will travel just slightly differently than if I intentionally pulled the slide to the left when charging the first round.  During the auto reload, the direction rearward and then forward is constant from shot to shot in direction and force.  A manual slide angle during a slingshot MAY make a slight difference in the position of the barrel when it is in battery.  Very slight.  Enough to notice at 100 yards, probably not a problem at 25. 

Today, I am going to do a lot of checking on surface finishes, sharp edges, anything that would affect the final position of the barrel once locked up.  Keep in mind that there has to be clearance, but the barrel should lock up consistently on one side of the clearance or the other from shot to shot.  It does exactly that after the first round.  I gotta figure out why!!  Might be as simple as consciously pulling the slide to one side or the other during release of the first round.

[Joe L]

I spent a lot of time in the shop this morning and I can't find anything obvious.  The new Primary Machine barrel had one edge that seemed a little high to the touch so I knocked that down with a stone and put it back together for the trip to the 200 yard range in New Mexico this coming week. 

Even if I have to waste the top round in a reload, I'm going to stick with it the way it is.  I'll just load 11 or 16 and shoot 2 or three 5 shot groups, probably 2 just to avoid adding so much weight that the recoil response changes.  Believe me, everything matters, but not much is too significant compared to the shooter's vision, patience, and state of mind!!   

This is fun.  This is not easy.

Joe