Help choosing head size of pellets.

[Nate the airgunner]

I was using JSB 15.9 grain pellets, but im going to quit using them because the damage so easily.

So, Im going to order a tin of 500 H&N Field Target Trophy pellets for the Trail, but, they are available in either head size of 5.53 mm, 5.54 mm, and 5.55 mm, Im thinking of getting 5.54s, because they are in the middle, so hopefully not loose fitting, or tight fitting. Give me your feedback to help me out please.

[MustangMike]

Look up the head size of the jsb's or if you can measure the head of a jsb. A digital caliper would be the best route to check..

[justindfish]

I shoot the 5.53's in my Trail NP and they fit and shoot very good 5.54 may be to tight.

[Magman116]

In My Trail NP .22, I have used the 5.53 and the 5.54 head size in the FTT.  The 5.53 gives higher velocity.  That tells me the 5.54s fit too tight to my barrel.  Yours might be different.

[bodybag0]

In My Trail NP .22, I have used the 5.53 and the 5.54 head size in the FTT.  The 5.53 gives higher velocity.  That tells me the 5.54s fit too tight to my barrel.  Yours might be different.

Same with my trail NP.  I'd stay with the 5.53

[mtsheron70]

I shoot the 5.5 and they do just fine.  Going to chrony them this week as well.

[VAFarmer]

Mic the current ones first, and then step up. 

Sort thru, chances are you will find a few that have larger head size.   Also mic any other brands you have around.

Sort to within a 1 thousandth.  I.E.  if most of the JSB's mic at .2155, then go .2155 to .2165.  then around .2165 to .2175, and so on, and so forth.   Convert to mm.
5.53 starts to work on most everything with a slightly bigger bore.   

Others are right, you want to just go big enough that it helps to tighten up groups.  NO bigger.   More area touching translates into more friction.

God bless,

Farmer

[Nate the airgunner]

Ill most likely get the 5.53 mm now, thanks all for the help.