IMR Classic
IMR SR 4756
A dual-purpose shotshell and handgun powder from IMR's SR (Sporting Rifle) family of small-kernel extruded propellants, used for field shotshell loads and mid-range handgun work.
Discontinued, and missed by people who loaded field shotshells and mid-range handgun ammunition with it. SR designated IMR's small-kernel extruded family, and 4756 was the slower survivor, useful for heavier shotshell payloads and for medium-pressure .45 ACP and .38 Special. Nothing current supports it: use archived manuals only, and be wary of the third-party figures floating around for it.
- 12 gauge field loads
- 20 gauge field loads
- .45 ACP
- .38 Special
Who has IMR SR 4756 today
Checked October 10None of the retailers we track list IMR SR 4756 right now. See what is in stock.
Discontinued. Canisters still circulate, but the maker no longer produces it — and load data for it may be withdrawn or archived.
Specifications
| Manufacturer | IMR |
|---|---|
| Product family | IMR Classic |
| Status | Discontinued |
| Application | shotshell, pistol |
| Grain form | extruded |
| Lee VMD (bulk density) | 0.1100 cc per grain · 0.59 g/cc |
| Composition | single-base |
| Typical cartridges | 12 Gauge, 20 Gauge, 45 ACP, 38 Special |
Grain shape
Small extruded kernels with tube geometry, so a steadier pressure curve than an equivalent flake, and small enough to meter reasonably through a pistol measure. It is not a flake powder and does not behave like one.
Why geometry decides burn rate more than chemistry does: Shape Is the Product.
Discontinued. Hodgdon no longer lists this powder among current IMR products and it does not appear on Hodgdon's current relative burn rate chart. No manufacturer product page remains; treat published characteristics from third-party sources with caution and use only data from a current or archived manufacturer manual.
This powder is obscure enough in the US that its practical character is thinly documented. The note above is deliberately short rather than padded.
Data confidence
We flag entries we could not fully verify rather than presenting them as solid:
- Discontinued — no live manufacturer product page; details drawn from archived or secondary manufacturer material.
Sources
The specifications above come from IMR's own published documentation, linked below. The two “RCM's read” sections are ours, not theirs — our assessment of what this powder is like to load, drawn from its published characteristics and from what handloaders consistently report. No manufacturer endorses them and no source below backs them. If you think we have one wrong, tell us — we would rather fix it.