Pellet Head Size Investigations

I got a P35 in 177 (and 22) in June of this year and have enjoyed figuring out what pellets it likes and making other adjustments. I've mainly been using H&N 10.65 grain pellets including the copper plated "Power", the Barracuda, and the Barracuda Match in both 4.5 and 4.52 head size. I initially noticed the Power shot better than the 4.52 Match I had on hand and wondered if it was the 4.5 head size of the Power. A tin of 4.5 Baracuda seemed to confirm that.

Then I noticed a tin of Crosman 10.5 grain in my collection and tried them, not expecting much. To my surprise they shot as well as the H&Ns. I shot a 184 with this gun on the 30 yard challenge with both the H&N Baracuda Match and the Crosman 10.5s. Since the Crosmans were so much cheaper I got a couple more tins. They don't shoot even close to the same. Why? Suspecting head size, I ordered a PelletGauge. It arrived yesterday and I started testing.

I had 18 from the "Good Tin" of Crosmans left to test. So I tested those and a sample of 20 pellets of several other types:

Good Crosmans were between 4.55 and 4.51 with most pellets at 4.54
First tin of bad Crosmans ranged from 4.55 to 4.46 (the full range of the gauge) with 4.54 and 4.52 being the most common
Second tin of bad Crosmans also had the full range of sizes with 4.51 and 4.46 the most common

Based upon these results I decided there was indeed a head size difference in the Crosman tins. I decided to test the other types I had been shooting.

Baracudas were 4.54 to 4.5 with the highest quantity 4.52.

Baracuda Power were 4.52 to 4.49 with the greatest quantity at 4.51

I opened a tin of Baracuda Match 4.5s I have not shot and they measured 4.5 to 4.46 with 4.5s the most common.

Baracuda Match 4.52s were all 4.53 to 4.51 with 4.52 the most common.

The similarity of the Match 4.52s to the others I thought shot better caused me to retest accuracy and I found they shoot well at this point. I am not sure if the gun has gotten broken in or my previous testing was bad.

Then I took the tin of Crosmans with the most 4.46 head size pellets and sorted out 10+ for a couple more groups. They were bad, well over an inch at 100 feet (which I used for all the accuracy testing). So it seems my gun does not like small head size.

Then I sorted the rest of that tin of nearly 500 pellets. I got usable quantities of all 10 head sizes of the gauge. Today I shot those. I won't go into the same gory detail on that exercise but it seems my gun likes 4.49 through at least 4.54 head size pretty well. I got 5 shot groups around 1/2 inch with all those sizes. 4.55 was not as bad as the small sizes but was a bit bigger. My little 20 pellet samples did not find 4.55 head sizes except in the Crosmans. Crosman Match pellets were more consistent in head size but the tendency of the 4.5s to trend toward the small end of the head size range for the outliers will probably cause me to use the 4.52s going forward. Or just stick with the slightly cheaper Baracudas. Their range of head size is bigger but they had nothing in the problematic small range. Given the variability in pellets, it is probably safer to pay slightly more to get the 4.52s.
 
I got a P35 in 177 (and 22) in June of this year and have enjoyed figuring out what pellets it likes and making other adjustments. I've mainly been using H&N 10.65 grain pellets including the copper plated "Power", the Barracuda, and the Barracuda Match in both 4.5 and 4.52 head size. I initially noticed the Power shot better than the 4.52 Match I had on hand and wondered if it was the 4.5 head size of the Power. A tin of 4.5 Baracuda seemed to confirm that.

Then I noticed a tin of Crosman 10.5 grain in my collection and tried them, not expecting much. To my surprise they shot as well as the H&Ns. I shot a 184 with this gun on the 30 yard challenge with both the H&N Baracuda Match and the Crosman 10.5s. Since the Crosmans were so much cheaper I got a couple more tins. They don't shoot even close to the same. Why? Suspecting head size, I ordered a PelletGauge. It arrived yesterday and I started testing.

I had 18 from the "Good Tin" of Crosmans left to test. So I tested those and a sample of 20 pellets of several other types:

Good Crosmans were between 4.55 and 4.51 with most pellets at 4.54
First tin of bad Crosmans ranged from 4.55 to 4.46 (the full range of the gauge) with 4.54 and 4.52 being the most common
Second tin of bad Crosmans also had the full range of sizes with 4.51 and 4.46 the most common

Based upon these results I decided there was indeed a head size difference in the Crosman tins. I decided to test the other types I had been shooting.

Baracudas were 4.54 to 4.5 with the highest quantity 4.52.

Baracuda Power were 4.52 to 4.49 with the greatest quantity at 4.51

I opened a tin of Baracuda Match 4.5s I have not shot and they measured 4.5 to 4.46 with 4.5s the most common.

Baracuda Match 4.52s were all 4.53 to 4.51 with 4.52 the most common.

The similarity of the Match 4.52s to the others I thought shot better caused me to retest accuracy and I found they shoot well at this point. I am not sure if the gun has gotten broken in or my previous testing was bad.

Then I took the tin of Crosmans with the most 4.46 head size pellets and sorted out 10+ for a couple more groups. They were bad, well over an inch at 100 feet (which I used for all the accuracy testing). So it seems my gun does not like small head size.

Then I sorted the rest of that tin of nearly 500 pellets. I got usable quantities of all 10 head sizes of the gauge. Today I shot those. I won't go into the same gory detail on that exercise but it seems my gun likes 4.49 through at least 4.54 head size pretty well. I got 5 shot groups around 1/2 inch with all those sizes. 4.55 was not as bad as the small sizes but was a bit bigger. My little 20 pellet samples did not find 4.55 head sizes except in the Crosmans. Crosman Match pellets were more consistent in head size but the tendency of the 4.5s to trend toward the small end of the head size range for the outliers will probably cause me to use the 4.52s going forward. Or just stick with the slightly cheaper Baracudas. Their range of head size is bigger but they had nothing in the problematic small range. Given the variability in pellets, it is probably safer to pay slightly more to get the 4.52s.
Hello JimD,

I just finished shooting a tin of JSB MRD 13.43 .177 cal that shot terrible. I do not have a pellet gauge but I do have a Pellet Sizer ( 4.51 ) and some of the pellets pushed through with almost no resistance and others required quite a bit of pressure. I had fliers about every 8 to 10 shots. With this new tin, I shot 23 MOA out of 25 and all the pellets pushed through equally. I'm not sure that any "brand" will offer a truly consistent head size.

ThomasT
 
I agree but the range of sizes in the Crosman pellets is much wider than in the H&N based upon my limited measurements. The H&N Match had an even tighter range. I need a 22 pellet gauge to be sure but so far I think my P35-22 is more tolerant. But I found it liked Baracuda Match and it has shot that almost exclusively. Either head size works fine, however.
 
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I spent enormous time checking+sorting with pellet gage and ended up putting it aside. I realized it is not precise enough for sorting.
I just ordered the TRobb sizer last week, it is in the mail somewhere above the pond as we speak.
I am planning to re-size the head and resize the skirt to the bore instead of sorting.
 
I spent enormous time checking+sorting with pellet gage and ended up putting it aside. I realized it is not precise enough for sorting.
I just ordered the TRobb sizer last week, it is in the mail somewhere above the pond as we speak.
I am planning to re-size the head and resize the skirt to the bore instead of sorting.
Hello bigHUN

Hope you will post a thread here on the Forum after you have used the TRobb.

ThomasT
 
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I spent enormous time checking+sorting with pellet gage and ended up putting it aside. I realized it is not precise enough for sorting.
I just ordered the TRobb sizer last week, it is in the mail somewhere above the pond as we speak.
I am planning to re-size the head and resize the skirt to the bore instead of sorting.
I'd like to know how you plan to resize the skirts and do you plan to adjust the pellet length at the same time if at all?
TKS
 
I wanted to get the H.M pellet sizer, they show separate insert for the head and separate insert for the skirt re-sizing. But looks like that video on YT was just a teaser from 2019.
Then I researched the RSterne tools, but they have only a single size = push through, cannot stuck two inserts on top of each other.
Ordered the TRobb only as a temporary solution, it is a tapered hole and I don't know how the ration (head to skirt) will work. This shall give me some buffer time over winter to make something similar as the HEN.
What I don't see with any pellet sizers is ---- to flatten the skirt rear edge. Just take a look any higher magnification jewellery lupe and have a closer look at your pellets and you will see what is my concern. We crown the barrels but the pellets skirts are uneven edges....
 
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I may try putting more H&Ns through the pellet gauge to get enough to try them at different head sizes. But what my testing of the Crosmans told me is my gun doesn't seem to care about the head size as long as it is not at the extremes of the range. That would mean that a more consistent pellet, like a H&N, should shoot the same regardless of the small variations in head size they have. I'm thinking of standardizing on the Baracuda Match 4.52s because I saw none of them anywhere near the low end of the range my gun seems to detest. Almost all the Match 4.5s were OK but 1 or 2 of the 20 were small enough they might not shoot the same.

I agree that you can feel really loose pellets. My P35 is a side cocker but I still feel reduced loading effort on pellets with small head size. That suggests that skirts are also smaller. The velocities may have also been a little lower for the smallest head size pellets.