5.52mm vs 5.51mm pellets - What Gives?!

SmokeyJoe · April 26, 2024, 08:04:03 AM

Been zeroing an Air Arms S200 and newly purchased S410 TDR (very nice bit of kit!)

The S200 has done nicely with Air Arms Diabolo pellets. Lovely groups.

The TDR came with half a tin of BSA pellets, they struggled to make sub 2 inch groups at 40 yards. Threw some of the AA Diabolos in it and it was hole on hole. Phew, that confirms the barrel's not bent

Now need to buy more of these AA Diabolos and i see two options: 5.51mm or 5.52mm.

The ones we've been using are 5.52. Is there any reason to try the 5.51? I'd assume not due to possibility of falling out of the fiddly little magazines, but I'd be interested in thoughts on it and why the option is there. Here's a link, more to show our American cousins the sort of prices we Brits have to suffer on the wrong side of the pond.

https://www.ebay.co.uk/itm/114130828645?var=414387472745

SmokeyJoe · April 26, 2024, 08:06:36 AM

PS - I THINK we are using 5.52, the tin only says 5.5mm for some stupid reason!

jaeger88 · April 27, 2024, 01:07:40 AM

Air Arms pellet tins are generic Joe, & printed on the lid of the tin with the caliber. if you look on the bottom of the tin, it should have a label giving the actual pellet size. 5.50/5.51/5.52. The same label also gives other information, like, date of manufacture etc.

If you get bored Joe, Air Arms also do a colouring book. You have to supply your own crayons though.

SmokeyJoe · April 27, 2024, 04:54:49 AM

haha, why thank you Sir.

No, I mean, why should I?

Ok so now i know where the label is, wanna enlighten me on the different choices and whether 0.1mm extra tight skirt (steady) will give me lasers at 1000 yards with 10.7 fpe?

Don't worry, you can give your real opinion, nobody will jump on you (unless I organise a seance for a second opinion)

jaeger88 · April 27, 2024, 08:03:49 AM

Are 5.51's better than 5.52's ?.
The answer to that one is................I don't know the answer.
Individual rifles are all different, yours could prefer either.
Trial & error is the only way to find out.

jaeger88 · April 27, 2024, 09:05:09 AM

You WILL let me know which is more accurate at 1,000 yds though, wont you ?.

SmokeyJoe · April 28, 2024, 02:19:08 AM

Yes of course. I'll just have to factor in the 'curvature of the earth' then I'll let you know.

Did you say you use a pellet resizer? Sometimes the pellets drop out of the TDR's magazine, I am wondering if a pellet resizer may help prevent that

jaeger88 · April 28, 2024, 04:44:15 AM

OK, well don't forget to dial in temperature, wind, humidity, altitude & of course, Coriolis effect as well.

Unfortunately the pellet sizer's I have can only size down, not up. So that's not going to help you at all. Is this a problem with the S200 mags, TDR mags or both ?. Ive not had that problem with my S501 .177 Mags.

Basically, in their simplest form, pellet sizer's are just a tapered tube, with the exit hole of the desired diameter. You just push a pellet all the way through. You can get em from Amazon for an Ayrton Senna.(10 English dollars), The better quality ones are made by T R Rob, & are adjustable.

SmokeyJoe · April 28, 2024, 04:50:46 AM

Quote from: jaeger88 on April 28, 2024, 04:44:15 AMOK, well don't forget to dial in temperature, wind, humidity, altitude & of course, Coriolis effect as well.

Unfortunately the pellet sizer's I have can only size down, not up. So that's not going to help you at all. Is this a problem with the S200 mags, TDR mags or both ?. Ive not had that problem with my S501 .177 Mags.

Basically, in their simplest form, pellet sizer's are just a tapered tube, with the exit hole of the desired diameter. You just push a pellet all the way through. You can get em from Amazon for an Ayrton Senna.(10 English dollars), The better quality ones are made by T R Rob, & are adjustable.

Aaah, i see. I was under impression the resizer could flare the skirt out to a slightly bigger OAD. Ignore me, I'll put my dunce cap back on.

I see, so I can see why the resizer would be nice for a bit more consistency, especially with some of the junk pellets I've seen!

jaeger88 · April 28, 2024, 04:53:31 AM

Sorry, just re read your last message & you said TDR mags.
T R Robb himself, says he doesn't think pellet size makes much difference to accuracy, unless they are so undersized they don't engage the rifling properly. The sizer does make pellets more uniform though, & that's where he believes the accuracy improvement comes from. Probably using quality pellets of a uniform weight helps too.

gitano · May 02, 2024, 08:33:04 AM

What I don't know about air rifles would fill volumes. Yet here I am commenting. All I can add is my experience with centerfire ammo.

Bullets for the .44 Rem Mag come in two diameters: 0.429", and 0.430". The 0.429" bullets shoot "patterns" from my revolvers, the .430s shoot groups.

Soviet-made rifles have bores that range in diameter from 0.306" to 0.314". The larger the bore, the crappier they shoot. Small-bored rifles get .308 bullets, large-bored rifles get .311 bullets. I had a brand new Soviet M44 that couldn't keep all of its shots on a 4-FOOT X 3-FOOT piece of sheetrock at 40 paces!

From what I've read, skirt diameter on pellets is critical to precision. That said, 0.01mm is 0.00039". While "stranger things have happened", it would certainly surprise me that that would make a SIGNIFICANT difference in precision. On the other hand, if it didn't, why would 'they' make the two sizes? Personally, I'd expect the bigger ones to shoot straighter, BUT, I'd shoot the ones that ACTUALLY shot the straightest. (Duh).

Paul

PS - Regarding pellet resizers: To make 'em bigger, seems like a cone one could push into the skirt to 'over' enlarge it, followed by pushing the pellet through the 'tube' of desired size, would be a method for "sizing up".

Paul

PPS - Kinda wish I had an excuse to get a nice Pre-charged pneumatic rifle like one of those.

Paul

gitano · May 02, 2024, 08:43:16 AM

Too bad you guys get intercoursed on firearms-related components.

Paul

Jamie.270 · May 03, 2024, 05:30:45 AM

Quote from: gitano on May 02, 2024, 08:43:16 AMToo bad you guys get intercoursed on firearms-related components.

Paul

Just as egregious is the near minuscule FPE limit imposed on airguns over there.
I'd like to have a .25 cal PCP myself. something that will push a lead pellet to 700-900 FPS.
But I struggle with justifying the cost of the compressor.

gitano · May 03, 2024, 06:10:27 AM

I have the exact same wish and hesitancy.

The FPE restriction, while stupid and egregious, at least "makes sense", in the context of the British authority's restricting firearms. To illustrate what I mean, our "shotgun only" hunting states are equally illogical. You can't use a "rifle" to hunt with, but you CAN use a shotgun, with a slug, from a shotgun WITH A FULLY RIFLED BARREL that will cast that projectile at least 300 yd. If people in GB were allowed to use UNLICENSED pneumatic firearms of ANY FPE, then they would make them powerful enough to kill people. GB citizens CAN possess pneumatic arms with FPEs greater than 12, BUT, they have to be included on the owner's LICENSE.

I have always thought a .25 caliber PCP would be a great gun to have 'around'.

Paul